Alleged movement of U.S. forces into Karbala last week was an act of terrorism that violates bilateral security arrangements, an Iraqi official said. A lawmaker in the Sadrist political party, loyal to anti-American cleric Moqtada Sadr, said U.S. forces entered parts of Karbala last week. Tariq al-Khekany told the Voices of Iraq news agency that U.S. forces spent about six hours in a Sadrist stronghold in the city. "We condemn the said 'terrorist' operation, which stood counter to the (2008) security agreement, signed between Iraq and the United States," he was quoted as saying. U.S. combat forces withdrew to their military bases in Iraq in June 2009 under the terms of a bilateral Status of Forces Agreement with Baghdad. That agreement left Iraqi security forces in the lead of major operations. A series of attacks and bombings Monday killed at least 89 people. Iraqi officials blamed national security forces in part for the attacks. U.S. Secretary of State Hillary Clinton during comments Tuesday said that although no group had claimed responsibility for Monday's attacks, it was likely a sign that al-Qaida in Iraq was "trying to assert itself." Iraqis are considering whether some U.S. forces would stay beyond a Dec. 31 deadline to withdraw. Sadrists blame the U.S. military presence for many of the country's problems.