Iraqi insurgents from an Al-Qaida splinter group seized effective control of the city of Tikrit on Wednesday, expanding their offensive closer to the capital Baghdad.



On Tuesday, Sunni fighters from the rebel group known as Islamic State of Iraq and the Levant took control of much of Mosul, Iraq's second-largest city, in a major blow to the authority of the country's Shiite government. An estimated half a million residents have fled the economically important city.



Residents reached by telephone in Tikrit, the hometown of former dictator Saddam Hussein, said the Sunni militant group had taken over several police stations on Wednesday, with soldiers and security forces abandoning their posts.



Two Iraqi security officials confirmed Tikrit was under the control of the ISIL and said the provincial governor was missing. The city is 130 kilometers (80 miles) north of Baghdad.

State television reported late on Wednesday that Iraq's air force had gone into action against the militants in Salah al-Din province, south of Mosul, wiping out a rebel column on one major route.



The rebels are closing in on the country's largest oil refinery in Baiji. "Our understanding at this point is that the refinery remains in control of the government of Iraq," State Department spokesperson JenPsaki told reporters on Wednesday.

Prime Minister Nouri al-Maliki blamed a "conspiracy" for the massive security failure in Sunni-dominated Ninevah province that allowed the militants to seize Mosul. He didn't provide details but said that members of the security forces who fled rather than stand up to the militants would be punished.



"Today, the important thing is that we are working to solve the situation," Maliki said. "We are making preparations and we are regrouping the armed forces that are in charge of clearing Ninevah from those terrorists."



Meanwhile, 24 people were killed and 41 wounded when a suicide bomber set off his explosive belt inside a tent where tribesmen were meeting to solve a tribal dispute in Baghdad's Shiite neighborhood Sadr City, according to police sources.

In other develpoments on Wednesday, the U.S. State Department said that the U.S. was ready to provide "any appropriate assistance" to the Iraqi government to deal with the deteriorating security situation.

At Turkey's rerquest, NATO held an emergency meeting on Wednesday night to discuss the taking of some 80 Turkish citizens hostage by the Iraqi insurgents. It was described as being for information purposes and not under Article 4 of NATO's founding treaty, which permits a NATO member to ask for consultations with allies when it feels its territorial integrity is threatened.

The stunning assault by the al-Qaida offshoot saw black banner-waving insurgents raid government buildings in Modul and Tikrit, push out security forces and capture military vehicles as residents fled for their lives.



Mosul is the capital of Ninevah province, whose governor, Atheel al-Nujaifi, told reporters that "Mosul is capable of getting back on its feet and getting rid of all the outsiders." The authorities planned to mobilize residents into popular militias that would play a role in retaking the city, he said.



Ninevah and the neighboring Sunni-dominated province of Anbar share a long and porous border with Syria, where the Islamic State claimed on Wednesday to have encircled the city of Deir el-Zour.



"They have surrounded the city. There are no entrances or exits left for people to flee," said a Syrian activist in the region who has contacts inside Deir el-Zour and who uses the name Salar.



There were no immediate estimates on how many people were killed in the assault on Mosul, but the rampage sent an estimated 500,000 people fleeing from the city and surrounding areas, according to the International Organization for Migration.

Some simply crossed to the eastern bank of the Tigris River to avoid the worst of the fighting, while others made their way to the Ninevah countryside or sought refuge in the nearby semiautonomous Kurdish region.

