Senior US military sources in Iraq have told the BBC they do not believe reports that the leader of al-Qaeda in Iraq has been injured in fighting.
Masri is believed to have received training in Afghanistan
Arab TV stations said early on Friday that Abu Ayyub al-Masri, also known as Abu Hamza al-Muhajir, had been hurt during clashes north of Baghdad.
The reports said that the incident had occurred in Balad.
Masri took over as the leader of al-Qaeda in Iraq after the death of Abu Musab al-Zarqawi in a 2006 US air raid.
Little is known about Masri - the US military has said it believes him to be an Egyptian militant based in Baghdad.
ABU AYYUB AL-MASRI
Originally from Egypt
Known as Muhajir - which means 'immigrant' in Arabic
Trained in Afghanistan
Helped Zarqawi set up first al-Qaeda cell in Iraq
Named as al-Qaeda in Iraq leader in June 2006
He is understood to have trained in Afghanistan and helped Zarqawi form the first al-Qaeda cell in the Iraqi capital.
A statement posted on a website used by Islamic militants in June 2006 announced that he would take over as the leader of al-Qaeda in Iraq after Zarqawi was killed in a US air strike.
The statement said he had a history of fighting a holy war and that he had been unanimously elected as the group's new chief.
There is currently a $5m US bounty on Masri's head.