BAGHDAD ��" The killing of al Qaeda's top two leaders in Iraq this week extends a string of smaller successes that may be eroding the group's ability to threaten security, military officials and analysts said on Thursday. The gains reported by US and Iraqi officials against the Sunni Islamists look significant, coming at a time of vulnerability created by a March 7 election that produced no clear winner and what is shaping up to be a protracted political vacuum. "We have arrested dozens of top figures of al Qaeda and got information from them that is very important. The arrests will continue for weeks and these weeks will be black for al Qaeda," Baghdad security spokesman Maj. Gen. Qassim al-Moussawi said. "We have information that most of the remaining leadership of al Qaeda has begun to flee Iraq. We have issued orders to close the border and check people leaving," he told Reuters. The blows against al Qaeda came to light after the killing by Iraqi and U.S. forces on Sunday of Abu Ayyub al-Masri, al Qaeda's leader in Iraq, and Abu Omar al-Baghdadi, the purported head of a local affiliate, the Islamic State of Iraq. US officials called the killings a potentially devastating blow and Moussawi said al Qaeda in Iraq was in a "state of confusion and disarray" -- a view shared by some experts. "Members of al Qaeda understand from day one that one day they will die, and the network's structure is built on people who can be replaced," said Mustafa al-Ani, an analyst at the Dubai-based Gulf Research Center. "But killing leaders has an impact because their replacements may not be of the same quality. The quality of al Qaeda in Iraq is no doubt being eroded," he added. On Thursday, Moussawi told reporters of the capture of a man called Manaf Abdul Rahim al-Rawi in Baghdad on March 11 at the start of an anti-al Qaeda operation codenamed "Lion's Leap" and which led up to the killings of Masri and Baghdadi. That operation began just days after the inconclusive parliamentary elections and amid fears that political uncertainty over the formation of a government would result in a spike in sectarian violence. Minority Sunnis backed the alliance that won the most seats, and will be angry if they are not in the next government. Frustrations among Sunnis, who dominated Iraq under Saddam Hussein, over the rise of Shi'ite power following the 2003 U.S.-led invasion fueled an insurgency and the sectarian war. Rawi's capture helped Iraqi security forces track down other al Qaeda leaders, Moussawi said. Rawi -- an Iraqi born in Moscow in 1975 and a member of al Qaeda since 2003 -- supervised some of the worst attacks Iraq has seen, including coordinated assaults by suicide bombers on government ministries and hotels over the past year, he said. Over the past month, the US military has sent out a flurry of news releases proclaiming almost daily that senior figures of al Qaeda in Iraq have been killed or detained.