Signs emerged that the Islamic State of Iraq and Levant is backed in its campaign by former military officers and other members of ousted dictator Saddam Hussein's regime — including a force led by Izzat Ibrahim al-Douri, the late leader's former deputy who escaped the 2003 U.S.-led invasion and eluded U.S. and Iraqi forces ever since.
As world leaders expressed alarm over the destabilization of large parts of the country by fighters from the militant group known as the Islamic State of Iraq and the Levant, the U.N. Security Council met on the crisis, but there is little prospect of any action by the body.
President Barack Obama said Iraq will need more help from the United States, but he did not specify what it would be willing to provide. Senior U.S. officials who spoke on condition of anonymity because they were not authorized to discuss the matter by name said Washington is considering whether to conduct drone missions in Iraq.
In the north, Kurdish security forces took over an air base and other posts abandoned by the Iraqi military in ethnically mixed Kirkuk, a senior official with the Kurdish forces said. He denied they had taken over the oil-rich city.
Prime Minister Nouri al-Maliki asked parliament this week to declare a state of emergency that would give him increased powers to run the country, but the lawmakers Thursday failed to assemble a quorum to do so.
The Islamic State aims to create an Islamic emirate spanning both sides of the Iraq-Syria border. It has been able to push deep into parts of the Iraqi Sunni heartland once controlled by U.S. forces because police and military forces melted away after relatively brief clashes.
Two senior intelligence officials told The Associated Press that an armed group led by al-Douri, the Naqshabandi Army, and other Saddam-era military figures joined the Islamic State in the fight. In Saddam's hometown of Tikrit that was overrun by militants Wednesday, witnesses said fighters raised posters of Saddam and al-Douri. The two officials spoke on condition of anonymity because they were not authorized to talk to the press.
The involvement of Saddam-era figures raises the potential to escalate the militants' campaign to establish an al-Qaida-like enclave into a wider Sunni uprising. That could only further the momentum toward turning Iraq's sectarian and ethnic divisions in to a geographical fragmentation.
The Islamic State issued a triumphalist statement declaring that it would start implementing its strict version of Shariah law in Mosul and other regions it had overrun. It said women should stay in their homes for modesty reasons, warned it would cut off the hands of thieves and told residents to attend daily prayers. It told Sunnis in the military and police to abandon their posts and "repent" or else "face only death."
"People, you have tried secular regimes ... This is now the era of the Islamic State," it proclaimed.
Baghdad does not appear to be in imminent danger of a similar assault, although Sunni insurgents have stepped up car bombings and suicide attacks in the capital recently.
With its large Shiite population, the capital would be a far harder target for the militants. So far, Islamic State fighters have stuck to the Sunni heartland and former Sunni insurgent strongholds where people are already alienated by al-Maliki's Shiite-led government over allegations of discrimination and mistreatment. The militants also would likely meet far stronger resistance, not only from government forces but by Shiite militias if they tried to advance on Baghdad.
Iraqi officials and analysts said the ISIL assault is being helped by sympathetic Sunnis, including former army officers and other remnants of Saddam's regime, which fell after the 2003 U.S.-led invasion.
Skirmishes continued in several areas overnight and into Thursday. Two communities near Tikirt — the key oil refining center of Beiji and the city of Samarra, home to a prominent Shiite shrine — remained in government hands, according to Iraqi intelligence officials.
They said ISIL fighters managed to take control of two big weapons depots holding some 400,000 items, including AK-47 rifles, rockets and rocket-propelled grenades, artillery shells and mortars. A quarter of the stockpiles were quickly sent to Syria in order to help the group's comrades there, they said.
Officers from the army that was disbanded after the invasion are helping coordinate the fight with the Islamic State, they said. Other armed groups involved in the attacks include the Army of the Men of the Naqshabandi Order, which is led by the top fugitive from Saddam's regime, Izzat al-Douri, and another known as the Iraqi Resistance Group, they said.
The officials provided the information on condition of anonymity because they were not authorized to divulge it publicly.
After Mosul fell Tuesday, al-Maliki asked parliament to give him the "necessary powers" to run the country under a state of emergency — something legal experts said would include powers to impose curfews, restrict public movements and censor the media.
After parliament failed to reach a quorum, Hakim al-Zamili, a lawmaker affiliated with firebrand Shiite cleric Muqtada al-Sadr, played down the apparent lack of support for the vote, saying al-Maliki already has enough power to take the necessary action.
"The problem is that soldiers are not resisting the armed groups," he said. "No soldier is ready to fire a shot against the gunmen."
The stunning advances by the Sunni militants are a heavy defeat for al-Maliki. His Shiite-dominated political bloc came first in April 30 parliamentary elections — the first since the U.S. military withdrawal in 2011 — but failed to gain a majority, forcing him to try to build a governing coalition.
Al-Zamili, a member in the parliament's defense and security committee, said armed groups such as Naqshabandi army, and former Baathists and army officers are fighting along with the ISIL.
Gunmen in Mosul continued to hold hostages at the Turkish consulate there.
Turkish officials are talking to militants in Mosul about freeing 80 people being held there, according to an official in the Turkish prime minister's office. The captives include 49 people who were seized in the Turkish consulate Wednesday, including the general consul and 31 truck drivers, said the official, speaking on condition of anonymity because he was not authorized to comment to reporters.
In addition to Mosul and Tikrit, the Islamic State and its allies among local tribesmen also hold Fallujah and other pockets of the Sunni-dominated Anbar province to the west of Baghdad.
Online video showed some Tikrit residents celebrating the takeover. As Islamic State fighters drove through largely empty streets in a captured military Humvee and a pickup truck mounted with an anti-aircraft gun, what appeared to be a few dozen people shouted "God is great," and celebratory gunfire could be heard. The video appeared authentic and was consistent with AP reporting.
The Islamic State's spokesman vowed to take the fight into Baghdad. In a sign of the group's confidence, he even boasted that its fighters will take the southern Shiite cities of Karbala and Najaf, which hold two of the holiest shrines for Shiite Muslims.
"We will march toward Baghdad because we have an account to settle there," he said in an audio recording posted on militant websites commonly used by the group. The statement could not be independently verified.
Meanwhile, Kurdish fighters from the ethnic group's autonomous enclave in the north showed signs of taking a greater role in fighting back against the Islamic State. Their role is a potential point of friction because both Sunni and Shiite Arabs are wary over Kurdish claims on territory outside their enclave.
Kurdish security forces known as peshmerga took over an air base and other posts abandoned by the Iraqi military in the ethnically mixed flashpoint city of Kirkuk, Brig. Halogard Hikmat, a senior peshmerga official told the Associated Press. But he denied reports the whole city was under peshmerga control.
"We decided to move ... because we do not want these places with the weapons inside them to fall into the hands of the insurgents," said Hikmat. Iraqi government officials could not be reached to confirm the account.
A force of 20 pickup trucks carrying Islamic State militants attacked peshmerga positions near the town of Sinjar, on a highway between Mosul and the Syrian border. The two sides battled for four hours late Wednesday night in a firefight that killed nine militants and wounded four peshmerga, Hikmat said.
Militants also attacked an Iraqi security checkpoint in Tarmiyah, 50 kilometers (31 miles) north of Baghdad, killing five troops and wounding nine, said officials, speaking on condition of anonymity because they were not authorized to talk to the media.
Hundreds of young men crowded in front of the main army recruiting center in Baghdad on Thursday after authorities urged Iraqis to help battle the insurgents.
Iranian Foreign Minister Mohammad Javad Zarif offered his country's support to Iraq in its "fight against terrorism" during a phone call with his Iraqi counterpart, Iranian state TV reported.
Obama did not specify what type of assistance the U.S. was willing to provide but said he had not ruled out any options.
"We do have a stake in making sure that these jihadists are not getting a permanent foothold in either Iraq or Syria, for that matter," Obama said during an Oval Office meeting with Australian Prime Minister Tony Abbott.
Shiite powerhouse Iran, which has built close ties with Iraq's postwar government, has halted flights to Baghdad because of security concerns and has intensified security measures along its borders.
Iranian President Hassan Rouhani blasted the Islamic State as "barbaric" and said that his country's highest security body will hold an immediate meeting to review the developments in neighboring Iraq.
The White House said Wednesday that the United States was "deeply concerned" about the Islamic State's continued aggression.
Human Rights Watch expressed concern about the group's advances, noting its history of violence and other abuses. The rights group also called on Baghdad to deal with the crisis "without the brutal tactics for which civilians elsewhere in the country have long been paying a heavy price," deputy Middle East director Nadim Houry said.
There were no reliable estimates of casualties or the number of insurgents involved, though several hundred gunmen were involved in the Tikrit fight, said Mizhar Fleih, the deputy head of the municipal council of nearby Samarra. An even larger number of militants likely would have been needed to secure Mosul, a much bigger city.
Mosul, the capital of Ninevah province, and the neighboring Sunni-dominated province of Anbar share a long and porous border with Syria, where the Islamic State is also active.
In addition to being Saddam's hometown, Tikrit was a power base of his once-powerful Baath Party. The former dictator was captured by U.S. forces while hiding in a hole in the area and he is buried south of town in a tomb draped with the Saddam-era Iraqi flag.
Schreck reported from Dubai, United Arab Emirates. Associated Press writers Qassim Abdul-Zahra in Paris, Bassem Mroue in Beirut, Nasser Karimi in Tehran and Desmond Butler in Istanbul contributed to this report.
Follow Adam Schreck on Twitter at www.twitter.com/adamschreck
Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.