The hugely expensive and complicated US mission to train Iraqi forces has had "mixed results," the report said, with the new Iraqi police forces having proved particularly problematic.
"The Iraqi Security Forces (ISF) have not yet developed as fast as the coalition planned and ... are not yet ready to take full responsibility for their country's security," the report said.
Signed by 16 lawmakers from both political parties, the report said the Pentagon must do a better job of informing congress of progress in training but stopped short of making a judgement on whether the US should continue the effort.
|At least 40 people were injured by a car bomb |
at a busy intersection in Baghdad [Reuters]
"This bipartisan report shows clearly that the president's plan to stand down our troops as the Iraqis stand up has been a failure to this point," Martin Meehan, the oversight and investigations committee chairman, said on Wednesday.
Todd Akin, the panel's most senior Republican party member, said Washington had no choice but to continue the training programme.
"Unless you basically give up on the whole project, the Iraqi security forces are just plain necessary because of the environment that exists within Iraq," he said.
The report came after two Republican senators earlier this week called a change of course in Iraq.
Thursday's bombing took place at a busy intersection in Baghdad where minibuses pick up and drop off passengers, Iraqi police said.
Police said the car bomb exploded in the mainly Shia district of Bayaa, an area which has been targeted in several bomb attacks.
Around 40 vehicles were set ablaze by the bomb which went off during the morning rush hour.
"It was a horrible explosion. Many, many people have been killed," one witness said.
Mortar bombs also struck the commercial area of Shorja in central Baghdad, killing at least two people and wounding 14, police said.
In the town of Salam Pak, 20 beheaded bodies were found on the bank of the Tigris river, police said.
All the victims were wearing civilian clothes and had their hands and legs bound, police said. Iraqi police cordoned off the area while they waited US forces had also been summoned.
Meanwhile, in the southern Iraqi city of Basra, a roadside bomb killed three British soldiers and wounded another during a foot patrol in the early hours of Thursday, Major David Gell, British military spokesman, said.