BAGHDAD,(Reuters) – U.S. and Iraqi government forces claimed a series of victories on Sunday against al Qaeda militants in a central province of Iraq that has been one of the heartlands of the Sunni militant insurgency.

On the stalled political front, Prime Minister Nuri al-Maliki’s office said he had refused to accept the resignations of six cabinet members from the main Sunni bloc in parliament, who triggered a crisis by quitting last week. But a senior official in the Sunni group, the Accordance Front, said the ministers would quit anyway.

U.S. forces said they had killed the top al Qaeda leader in Salahuddin province, Haitham al-Badri, whom they blamed for a pivotal 2006 attack on a Shi’ite shrine in the city of Samarra that was a turning point in the country’s sectarian conflict. They also said a week-long Iraqi police crackdown on al Qaeda in Samarra had netted 80 suspects. Among the other al Qaeda figures reported captured over the past few days were the group’s local leaders for the Salahuddin cities of Samarra and Tikrit, home town of ousted leader Saddam Hussein. The U.S. military said last week it had killed the al Qaeda leader in Mosul in the province further north.

U.S. and Iraqi officials frequently say they have killed or captured leading al Qaeda figures, and the precise role that any particular individual may have played in the shadowy militant group is often difficult to assess. But the announcements indicate a push against al Qaeda guerrillas in the large stretch of towns and cities that runs along the fertile Tigris River valley north of Baghdad.

U.S. forces identified the slain al Qaeda provincial chief Badri as the mastermind behind two attacks on the al-Askari mosque, a Shi’ite shrine in Samarra.

The first of those attacks, which destroyed the mosque’s famed golden dome in February last year, was the trigger for a sharp worsening in sectarian violence that has since consumed the country, killing tens of thousands of people. The second attack destroyed the mosque’s two minarets six weeks ago.

Separately, an Iraqi military officer said troops had captured al Qaeda’s leader for the city of Tikrit, named Talal al-Baazi. U.S. forces said the group’s leader for Samarra, whom they did not name, was also caught.

The U.S. military said more than 1,000 Iraqi troops had completed a security sweep which began on July 31, arresting 80 militant suspects, and quoted the Salahuddin governor as promising a development campaign to begin in coming days.

Washington says its military strategy of sending 30,000 additional troops to Iraq this year and spreading them in neighbourhoods is having success, but has complained about the failure of Iraqi politicians to make progress in the same time.

Deputy Prime Minister Salam al-Zobaie and five other ministers from the Accordance Front quit Maliki’s coalition government.

Maliki’s decision not to accept their resignations appears aimed at breaking the deadlock. But a senior parliamentarian from the Sunni group said they would quit anyway. “We are insisting on our position. For us, the matter does not end with Maliki accepting or rejecting the resignations,” Saleem al-Jubouri told Reuters. “We are talking about a programme. The issue is if he accepts or rejects our programme.”

In Baghdad, a barrage of mortar rounds fell at dawn on a petrol tation crowded with Iraqis queuing for fuel, killing 11 people, wounding 15 and destroying cars. Mortar rounds also fell at another petrol station nearby, wounding six more people.

Shortages mean Iraqis often have to line up for hours for fuel, where they are frequently targeted. Suicide bombers killed 70 people near two petrol stations last Wednesday.