Iraqi police commandos captured the leader of al-Qaeda in Iraq in a raid in the northern city of Mosul, Iraqi officials said Thursday, in what could mark a significant blow to the Sunni insurgency in its last urban stronghold.

This photo made available by the U.S. military purports to show al-Qaeda in Iraq leader Abu Ayyub al-Masri. (U.S. Military/Associated Press)Iraqi Defence Ministry Spokesman Mohammed al-Askari said the arrest of Abu Ayyub al-Masri — also known as Abu Hamza al-Muhajir — was reported by the Iraqi commander in Mosul, where insurgents have sought to establish a foothold after being largely uprooted from Baghdad and surrounding areas last year.

The U.S. military in Baghdad said it was "checking with Iraqi authorities to confirm the accuracy of this information."

Interior Ministry spokesman Maj. Gen. Abdul-Karim Khalaf said the arrest occurred "at midnight, and during the primary investigations, he admitted that he is Abu Hamza Al-Muhajir."

Khalaf told Iraqi state television that al-Masri was arrested during a police raid, but gave no other details.

"Now a broader investigation of him is being conducted," he said.

Al-Masri's capture would carry major symbolic value for Iraqi commanders, who have led operations in the Mosul area and have sought to counter worries that Iraqi forces lack the training and discipline to wage a head-on fight against insurgents.

But it's unclear how much the loss of al-Masri would disrupt al-Qaeda in Iraq or its long-term ability to wage suicide attacks and other strikes.

False alarms before

Al-Masri took over al-Qaeda in Iraq after its leader, Abu Musab al-Zarqawi, was killed June 7, 2006, in a U.S. air strike northeast of Baghdad.

The pace of insurgent attacks remained strong as al-Masri took charge.

"The commander of Ninevah military operations informed me that Iraqi troops captured Abu Hamza al-Muhajir the leader of al-Qaeda in Iraq," al-Askari told the Associated Press by telephone.

There have, however, been false alarms in the past about al-Masri. At least twice — in 2006 and in May 2007 — reports circulated that al-Masri was dead, but they were later proved wrong.

Any direct links between al-Masri's insurgents and the terror network of Osama bin Laden are murky, but al-Masri has followed a path that brought him into contact with some of bin Laden's top lieutenants.

U.S. officials said al-Masri — whose name means "The Egyptian" in Arabic — joined al-Qaeda camps in Afghanistan in the late 1990s and trained as a car bombing expert before travelling to Iraq after the U.S.-led invasion in 2003.

The U.S. military also alleged al-Masri is a previous member of the extremist Islamic Jihad in Egypt and a protege of Ayman al-Zawahiri, who became bin Laden's No. 2 after the group joined with al-Qaeda in 1998.

The Islamic State of Iraq, an umbrella organization that includes al-Qaeda in Iraq, last year announced an "Islamic cabinet" for Iraq and named al-Masri as "minister of war." The U.S. military had put a $5 million US bounty on al-Masri.