Al Qaeda in Iraq announced in a Web statement posted Monday that a militant named Abu Hamza al-Muhajer was appointed the group's new leader to succeed the slain Abu Musab al-Zarqawi.
Described in the message as a "beloved brother with holy war experience and a strong footing in knowledge," Abu Hamza al-Muhajer is almost certainly an alias, reports CBS News correspondent Elizabeth Palmer, and so far no one seems to know much about him or whether he's an Iraqi or another foreign fighter like Zarqawi.
"Al Qaeda in Iraq's council has agreed on Sheik Abu Hamza al-Muhajer to be the successor for Abu Musab al-Zarqawi in the leadership of the organization," said a statement signed by the group on an Islamic militant Web forum where it often posts messages.
The authenticity of the statement could not be independently confirmed.
Earlier Monday, a U.S. military doctor said that al-Zarqawi died 52 minutes after an air strike against his safe house northeast of Baghdad and that an autopsy showed his injuries were consistent with those caused by a bomb blast.
Col. Steve Jones, command surgeon for Multinational Forces said that al-Zarqawi's spiritual adviser, Sheik Abdul-Rahman, was killed instantly. He added that an FBI test positively identified al-Zarqawi.
"Blast waves from the two bombs caused tearing, bruising of the lungs, and bleeding," Jones said.
"We have clear evidence that he died of blast injuries. There is no evidence to suggest that he was beaten, and I have no reason to suspect that that happened."
The al Qaeda in Iraq leader also suffered head and facial wounds, bleeding in his ears and a fracture of his lower right leg.
Maj. Gen William Caldwell, a spokesman for the U.S. military in Baghdad, said an F-16 dropped a 500-pound bomb on the house at 6:12 p.m. Wednesday. A second bomb followed immediately after.
U.S. troops arrived at 6:40 p.m. and found Iraqi police at the site. He said a coalition medic treated al-Zarqawi, who lapsed in and out of consciousness.
"The medic registered no pulse or respirations, and at 7:04 p.m. on 7 June, realized that Zarqawi was dead," said Caldwell. "This is approximately 24 minutes after the coalition forces arrived, or approximately 52 minutes after the first air strike on the safe house."
"It was evident he had massive internal injuries," Caldwell said.
He added that no decision had been made on what to do with the remains of al-Zarqawi and Rahman.
"These autopsies were performed to make a definitive determination as to the cause of both Zarqawi's and Rahman's deaths," Caldwell said. "The scientific facts provide irrefutable evidence regarding the deaths of terrorists will serve to counter speculation, misinformation and propaganda."
The airstrike killed another man, two women and girl between the ages of 5 and 7 who were in the house.
Zarqawi's killing has meant a wartime windfall for the coalition forces, reports Palmer. In the past 48 hours, the U.S. military announced it has carried out 140 major operations, killed 32 insurgents and detained 178, including one described as a high-value target with a $50,000 price on his head.
An Iraqi man who was one of the first people on the scene of the U.S. air strike targeting al-Zarqawi said he saw American troops beating a man who had a beard like the al Qaeda leader.
The witness, who lives near the house where al-Zarqawi spent his last days, said he saw the man lying on the ground near an irrigation canal. He was badly wounded but still alive, the man told Associated Press Television News.
The Iraqi, identified only as Mohammed, said residents put a bearded man in an ambulance before U.S. forces arrived.
"When the Americans arrived they took him out of the ambulance, they beat him on his stomach and wrapped his head with his dishdasha, then they stomped on his stomach and his chest until he died and blood came out of his nose," Mohammed said, without saying how he knew the man was dead.
No other witnesses have come forward to corroborate the Iraqi man's account that al-Zarqawi was beaten.
Lt. Col. Thomas Fisher of the 1st Battalion, 68th Armored Cavalry said his men showed up at the site about five minutes after the blast and cordoned it off. He said a patrol was in the area already.
"We didn't know it was Zarqawi, we just knew it was a time-sensitive target," he said at the scene early Saturday. "We suspected who it was."