BAGHDAD - Iraqi security forces were tipped off to last week's suicide bombings in Baghdad just hours before the blasts killed 127 people, a Shiite lawmaker said yesterday after a closed-door parliamentary briefing by the nation's defense minister.

But the tip was too vague and came too late to stop the bombings, Defense Minister Abdul-Qader al-Obeidi told lawmakers, according to the legislator, who attended the discussion.

The special session of parliament was called to question Iraq's senior security chiefs, including the defense and interior ministers, about security gaps that allowed the third attack since summer against government sites in the capital.

"The ministers said that they cannot guarantee that such operations will not be repeated," Shiite legislator Haider al-Ibadi told reporters after the session ended.

Ibadi said officials from the Interior Ministry and Baghdad security obtained information about a possible bomb plot Tuesday. "And this information was spread to the security forces, but this tip lacked details, and there was little time for the security forces to stop them," he said.

None of the security officials - who also included the national security minister and the Iraqi intelligence chief - spoke publicly after the session.

Later, Al-Iraqiya state television carried clips of Obeidi and Interior Minister Jawad al-Bolani addressing parliament. Those excerpts, however, did not include any comments about a tip-off before the attack.

In the televised excerpts, Bolani defended Iraqi security forces and said authorities thwarted attackers from hitting one of the targeted sites, the Labor Ministry. Bolani also praised Iraqi police for confronting an attacker in another area of Baghdad.

"I think that the security forces have carried out their duties, and the proof is that the terrorists were not able to reach their planned targets" in some cases, Bolani said in one excerpt broadcast on Al-Iraqiya.

Parliament wasn't satisfied.

Lawmakers took the ministers to task, demanding an adequate explanation for how suicide bombers slipped through security in heavily guarded downtown Baghdad to launch five bombs, all within an hour of each other.

Yesterday, a roadside bomb targeting a patrol killed three police officers in northern Iraq, said Police Col. Sherzad Morferi. The bomb wounded two others in the attack in the oil-rich city of Kirkuk, he said.

Americans continue to be targeted, too. A roadside bomb hit a U.S. vehicle in northwest Baghdad yesterday, injuring three American soldiers, said a military spokesman, Master Sgt. Nicholas Conner. He had no additional details.