BAGHDAD - The U.S. military had warned of an imminent attack hours before last week's deadly bombings in Baghdad, but the tip came too late to act on, Iraqi security officials said yesterday, as outraged lawmakers pressed for answers about Iraq's ability to protect the capital.

Even news that 13 al Qaeda-linked suspects have been detained in connection with the bombings did little to quell the angry parliament members, who shouted down security officials as they tried to defend their forces.

The grilling in parliament was the third session since Tuesday's attacks that put government officials and security brass on the hot seat. It also suggested that Prime Minister Nouri al-Maliki may need much bolder action to repair the government's image heading toward March elections.

So far, he shook up the Baghdad security command and some officers have been placed in custody for possible negligence after bombings that left at least 127 people dead and more than 500 wounded.

But many lawmakers - mostly political foes - have refused to let the government off the hook.

For them it was prime-time political theater with lengthy portions broadcast on state television. Some jabbed their fingers toward security chiefs and demanded more details and accountability about what went wrong.

"We need you to tell us the truth about when the Iraqi forces will be fully capable of protecting the country," said Maha al-Douri, a Shiite lawmaker.

The bombings were the third such attack since August against government buildings, raising serious questions about the abilities of Iraqi forces ahead of the withdrawal of U.S. combat troops at the end of August 2010.

The former head of Baghdad security command, Lt. Gen. Abboud Qanbar, took the brunt of the backlash yesterday. He was demoted to No. 2 after the blasts.

On the morning of the attacks, he said that Baghdad's security command received intelligence from the U.S. military that insurgents would soon carry out three attacks, including one in or near the protected Green Zone, home to the prime minister's office, parliament and the U.S. Embassy.

He said that the tip indicated that there would be two car-bomb attacks in the morning and another later in the day. Three major explosions shook Baghdad about five hours after the Americans notified the Iraqis.

Qanbar said that there was not enough time to chase leads or enough detail in the U.S. intelligence to reassign units.

U.S. military officials did not immediately respond to requests for comment.

Earlier, Interior Minister Jawad al-Bolani said that 13 suspects had been arrested in connection with Tuesday's bombings.

"There are 13 coffins waiting for criminals implicated in Tuesday attacks, and those criminals will be tried and convicted," al-Bolani told lawmakers.

He did not elaborate, but an official at his office later said that the 13 suspects are accused of being al Qaeda-linked insurgents who helped mastermind the bombings. They are the first arrests confirmed after last week's blasts.

The official spoke on condition of anonymity because he was not authorized to speak to media.

The U.S. military did not immediately confirm the arrests.

But even the announcement of arrests failed to calm lawmakers, who have been growing increasingly testy with the government since al-Maliki's blame-shifting tactics in a parliament address last week. The prime minister attributed security shortfalls to a host of problems, including political infighting and a lack of communication between security branches.

Al-Maliki and other government officials have all tried to counter criticism by citing accomplishments in security training and taking gradual control from U.S. forces.

"We do not need to hear about achievements. We are here to discuss the mistakes and the solutions to end these breaches," complained Waiel Abdul-Latif, a senior Shiite lawmaker.

Violence in Iraq has dropped off dramatically over the past two years, though insurgents have routinely targeted Iraqi security forces or staged high-profile bombings.

Yesterday, a car packed with explosives blew up near a passing police patrol in Fallujah, west of Baghdad, killing at least two people but missing the security chief who was the apparent target, a police official said.

The blast in Fallujah killed at least two guards accompanying police Col. Saad al-Shimari, who was not harmed. At least seven people were injured, said the official, who spoke on condition of anonymity because he was not authorized to speak to media.

Near the northern city of Mosul, a car bomb exploded next to a crowd of Iraqi army recruits, killing two people and injuring 19, said a Mosul police official, who also spoke on condition of anonymity. The attack occurred about three miles (five kilometers) east of the city, which is considered the last major urban base for Sunni insurgents.