Over 35,000 Saddam Hussein loyalists have regrouped, a former official of the Iraqi information ministry has said.
They have formed guerrilla formations like 'The Black Brigade' and 'The Revenge Army', Newsweek magazine quoted him as saying.
US intelligence officials, however, cannot quite decide if the guerrillas are centrally organised or just a bunch of ragtag 'deadenders', the magazine said.
The official told the magazine that Uday and Qusay Hussein had 'exercised real command and control' over the guerrillas.
Qusay and Uday, the magazine said, had roughly $100 million when they were killed. American soldiers also found Uday's briefcase in a rubble near his body.
On April 9, as Baghdad was falling to the Americans, Uday summoned his mother, who he wanted to see one last time, before disappearing, it said.
Nawaf al-Zaidan, the owner of the Mosul house where the brothers stayed during their final weeks, was found sitting nonchalantly in an American Humvee with his son, Shalan, after the brothers were killed, it said.
"Why is your house being bombed?" he was reported to have been asked by a neighbour.
"Uday and Qusay have been in my house for 23 days! They surprised me. They came and knocked on my door," Zaidan, who will probably receive the entire $30 million reward, said, according to the magazine.