The Iraqi Interior Ministry says 75 percent of al-Qaida in Iraq's terrorist network has been destroyed in the past 12 months.

An Interior Ministry spokesman, Abdul Kareem Khalaf, told a news conference in Baghdad Saturday that increased Iraqi patrols played a key role in the improved security situation. He said the terrorist network's activity is now limited to areas north of the capital.

Iraqi Interior Ministry: Most of Al-Qaida Network Destroyed in 2007

He did not elaborate on how the percentage was determined.

Iraqi Interior Ministry: Most of Al-Qaida Network Destroyed in 2007

Elsewhere in the capital, the top U.S. commander in Iraq, General David Petraeus, told reporters Saturday that al-Qaida is still a top concern despite some success against it. He said the U.S. military regards the group as the most significant challenge threatening Iraq.

Iraqi Interior Ministry: Most of Al-Qaida Network Destroyed in 2007

Also Saturday, the U.S. military said coalition forces killed three terrorists and detained about 40 suspects in separate operations targeting al-Qaida in central and northern Iraq.

The military said another operation in southern Iraq focused on what the military calls "Special Groups" that concentrate on rocket-propelled grenade and mortar attacks against coalition forces.

Also Saturday, Iraqi Prime Minister Nouri al-Maliki flew to London for what he said is a routine medical check-up. He told reporters at the airport in Baghdad that he would return home soon.