BAGHDAD – The United States and Iraq claimed a major victory against al-Qaida on Monday, saying their forces killed the terror group’s two top figures in this country in an air and ground assault on their safe house near Saddam Hussein’s hometown.

Iraqi Prime Minister Nouri al-Maliki announced the killings of Abu Omar al-Baghdadi and Abu Ayyub al-Masri at a news conference. U.S. military officials later confirmed the deaths, which Vice President Joe Biden called a “potentially devastating blow” to al-Qaida in Iraq.

The organization has proven resilient in the past, showing a remarkable ability to change tactics and adapt — most notably after its brutal founder, Abu Musab al-Zarqawi, was killed nearly four years ago in a U.S. airstrike. But some analysts contend the group was far stronger then and would likely have a harder time now replenishing its leadership and sticking to a timetable of attacks.

“The death of these terrorists is potentially the most significant blow to al-Qaida in Iraq since the beginning of the insurgency,” Gen. Raymond Odierno, the top U.S. commander in Iraq, said in a statement.

Al-Qaida in Iraq has remained a dangerous force as the United States prepares to withdraw most of its troops. The terror group has launched repeated attacks on civilian targets in Baghdad in an attempt to sow chaos and exploit political deadlock in the wake of the inconclusive March 7 parliamentary elections.

The announcement comes at a critical time for al-Maliki, who has staked his reputation on being the man who can restore stability to Iraq after years of bloodshed. The prime minister is locked in a tight contest with secular challenger Ayad Allawi to see who will form the next government. Al-Maliki’s coalition trails Allawi’s bloc by two seats in the 325-seat parliament, and neither has yet been able to secure enough support from other parties to muster a majority.

Allawi has charged that Iraqi security forces have been unfocused since the election. But Biden, President Obama’s point person on Iraq, said the deaths of the al-Qaida leaders underscored their overall improvement.

“The Iraqis led this operation, and it was based on intelligence the Iraqi security forces themselves developed,” Biden said in the White House briefing room.

The U.S. military said the early Sunday raid that killed the two al-Qaida leaders was launched after intelligence gathered during operations over the last week led security forces to the elusive leaders’ safe house about six miles southwest of Tikrit.

Al-Maliki said ground forces surrounded the house and that rockets were fired from the air. Al-Masri’s assistant and al-Baghdadi’s son, both suspected of being involved in terrorist attacks, also died in the raid and 16 other suspects were arrested, the military said.

Past Iraqi claims to have captured or killed al-Baghdadi turned out to be wrong, and the Islamic State of Iraq had twice issued denials of his capture.

Al-Qaida in Iraq emerged after al-Zarqawi pledged his allegiance to Osama bin Laden, leader of the global al-Qaida network, in October 2004.