Baghdad, Iraq ? Two suicide bombers disguised as police infiltrated the heavily fortified Interior Ministry compound in Baghdad and blew themselves up Monday during celebrations of National Police Day, killing 29 Iraqis.

The attackers died before getting near the U.S. ambassador and senior Iraqi officials at the festivities, but the blasts capped a particularly deadly week for American and Iraqi forces.

Iraqi police also were searching for an American journalist who was kidnapped Saturday by gunmen who ambushed her car and killed her translator in Baghdad.

Jill Carroll, a 28-year-old freelancer for The Christian Science Monitor, was seized in Baghdad’s predominantly Sunni Arab al-Adel neighborhood. Police said she went there to see a Sunni Arab politician.

The escalating violence after the Dec. 15 parliamentary elections – at least 498 Iraqis and 54 U.S. forces have been killed – came as Iraq’s electoral commission again delayed releasing the results of the vote.

An Internet site known for publishing extremist material from al-Qaida in Iraq leader Abu Musab al-Zarqawi carried a claim of responsibility for Monday’s suicide attack, saying it was in revenge for the torture of Sunni Arab prisoners at two detention facilities run by the Shiite-led Interior Ministry.

“The lions of al-Qaida in Iraq were able to conduct a new raid on the Interior Ministry, taking revenge for Allah’s religion and the Sunnis, who are being tortured in the ministry’s cellars,” the statement said.

The claim, which could not be independently verified, referred to reports that more than 100 abused prisoners were recently found in the jails – bolstering complaints by Sunni Arabs about the treatment of detainees by Interior Ministry forces.

Another purported al-Zarqawi statement rebuked Sunni Arabs for participating in the parliamentary elections, saying they had “thrown a rope” to save U.S. policy.

Meanwhile, the U.S. military said eight U.S. troops – including four Alaska Army National Guard members – and four American civilians died aboard a U.S. Army Black Hawk helicopter that crashed Saturday. The military initially said only that eight passengers and four crew were aboard.