Qaeda-linked Islamic State in Iraq denies head captured

(Adds details, background)

DUBAI, May 12 (Reuters) - Al Qaeda-linked group the Islamic State of Iraq has denied Iraqi government reports that its leader Abu Omar al-Baghdadi has been captured.

Iraq's defence ministry announced in late April that Baghdadi had been captured, in what would be a blow to a weakened, yet still potent, insurgency pressing a rash of major bombings.

"We in the Islamic State of Iraq would like to show that the report ... is a lie and that we do not know in the first place the person whose picture was shown on the Iraqi satellite channel," the group said in a statement on an Islamist website.

"We bring glad tidings to the Islamic nation that the leader of the faithful, Sheikh Abu Omar al-Baghdadi ... is well."

Iraqi officials have in the past reported the capture or killing of senior al Qaeda operatives that later turned out to have been incorrectly identified.

Baghdadi is said to be the head of the Islamic State of Iraq, close to al Qaeda's main organisation in Iraq, which is led by Abu Ayyub al-Masri, also known as Abu Hamza al-Muhajir.

Some experts say they are unconvinced that Baghdadi exists. They say he is a fictional character invented by al Qaeda in Iraq as part of a media strategy to put an Iraqi figurehead at the top of an organisation that is otherwise foreign-run.

In April, Mohammed al-Askari, a spokesman for the Iraqi Defence Ministry, told al-Iraqiya state television that he could confirm Baghdadi's identity and that Iraqi security forces had been secretly following him. He said the arrest was carried out without U.S. military assistance.

If Baghdadi's arrest proves to be true, it could be seen as a victory for Iraqi forces, who are seeking to assert their own abilities as the U.S. force of 137,000 prepares to fully withdraw from Iraq by 2011.

The insurgency sparked by the U.S.-led invasion in 2003 had calmed since 2007 but April saw a spike in violence, with insurgents showing themselves still capable of carrying out frequent, large-scale bombings.

The spike in major bombings in recent weeks has raised doubts about security gains. U.S. combat troops are preparing to withdraw from Iraqi cities next month and Iraq faces national elections by early next year.

Reporting by Lin Noueihed; editing by Ralph Boulton