The Iraqi government on Tuesday displayed for the first time a picture of a man it says is the purported leader of an al-Qaida front group.
The arrest of Abu Omar al-Baghdadi, the head of the Islamic State of Iraq, could mark a setback for insurgents trying to intensify attacks after a relative lull.
His capture was announced by the Iraqi government last week but the claim met with skepticism due to similar announcements in the past that have proven false.
Iraqi military spokesman Maj. Gen. Qassim al-Moussawi said the government was certain the man arrested on April 23 was al-Baghdadi and showed the picture of a bearded man with short hair and downcast eyes, wearing a black T-shirt.
He offered no other proof of identity, saying the investigation was ongoing and security forces were still trying to glean information from the detainee.
The U.S. military has said it is working to verify who was captured.
If confirmed, the arrest would mark a major victory for Iraqi forces reeling from accusations that they are not prepared to take over their own security in the wake of a series of high-profile bombings, with more than 150 people killed over two days last week.
Not the first time
Iraqi officials, however, have reported al-Baghdadi's arrest or killing before, only to later say they were wrong. The U.S. military has even said al-Baghdadi could be a fictitious character used to give an Iraqi face to an organization dominated by foreign al-Qaida fighters.
In 2007, Iraq's government reported that al-Baghdadi had been killed and released photos of what it said was his body. Later, security officials said they had arrested al-Baghdadi. In both cases, the U.S. military said at the time it could not be confirmed and the reports turned out not to be true.
But a senior Iraqi security official said authorities were certain they had al-Baghdadi this time but did not want to release too much information because it could tip off members of his insurgent network.
"Al-Baghdadi is in our custody now and we have the full range of evidence to prove that," the official said on condition of anonymity because he wasn't authorized to release the information.
Information from al-Baghdadi led Iraqi authorities to arrest four people, including a woman, and seized three explosive belts in Diyala province, north of Baghdad, the official said.
He said the attacks had been planned to coincide with Saddam's birthday, which was Tuesday.
Relatives and supporters of the late Iraqi ruler, meanwhile, laid wreaths by his grave and chanted slogans against former President George W. Bush to mark Saddam's birthday in his native village.
Saddam would have turned 72 on Tuesday. He is buried in the Tigris River hamlet of Ouja, where he was born, about 70 miles north of Baghdad.
The former dictator was hanged in December 2006 in Baghdad after being convicted of crimes against humanity.