The leader of al-Qaeda in Iraq, Abu Ayyub al-Masri, has been arrested, according to media reports quoting the country's defence ministry.

Al-Masri, also known as Abu Hamza al-Muhajir, was detained in the northern city of Mosul, reports said.

The US military in Iraq said it was so far unable to confirm the reports.

The Egyptian-born militant took over the leadership of the group from Abu Musab al-Zarqawi shortly after he was killed in a US air strike in June 2006.

Al-Qaeda in Iraq has been blamed for or has claimed responsibility for some of the bloodiest insurgent attacks in Iraq since the US-led invasion in 2003.

Joint operation

A spokesman for the Iraqi defence ministry, Mohammad al-Askari, told the Associated Press that he had been informed of Masri's capture by the Iraqi military in Nineveh province, of which Mosul is the capital.

"The commander of Nineveh military operations informed me that Iraqi troops captured Abu Hamza al-Muhajir, the leader of al-Qaida in Iraq," he said.

Interior ministry spokesman Maj-Gen Abdul-Karim Khalaf told al-Iraqiya TV that security forces had "arrested one of al-Qaeda's leaders at midnight and during the primary investigations he admitted that he was Abu Hamza al-Muhajir".

Gen Khalaf said a source close the al-Qaeda leader had informed police that he would be at a house in Mosul's Wadi Hajjar district at midnight on Wednesday.

Members of al-Qaeda are believed to have regrouped in the northern city since the beginning of the US troops "surge" last year.

A US military spokesman in Baghdad said he could not confirm that Masri had been arrested, but did not believe the reports to be true.

'Minister of war'

Al-Masri is believed to have helped Zarqawi form the first al-Qaeda cell in Baghdad.

After becoming leader, he vowed to "continue what Sheikh Abu Musab began" and avenge his death with attacks that would "turn your children's hair white".

In April 2007, he was named "minister of war" in the 10-man cabinet of the "Islamic State of Iraq".

Shortly afterwards, the Iraqi government claimed al-Masri had been killed in an "internal battle" between militants, but this was quickly denied by the group.

In an hour-long audio tape broadcast last month, he purportedly called for renewed attacks on US troops and noted the recent announcement that 4,000 had died in Iraq.

"We must celebrate this event in our special way, and make the defeated Bush join us in this celebration," he said.

PHOTO CAPTION:

Abu Ayyub al-Masri

BBC