BAGHDAD, April 18 (Reuters) - A group of al Qaeda bombers has slipped into Baghdad to carry out a wave of car bombs and suicide attacks, the U.S. military said on Friday. The unusual warning came after a spate of deadly bombings this week struck areas in northern Iraq, where al Qaeda Sunni Arab militants are known to be active. "Information collected by coalition forces states that numerous AQI (al Qaeda in Iraq) terrorists have entered the Baghdad area with the purpose of carrying out vehicle-borne improvised-explosive devices or suicide vest attacks in the Karkh district of central Baghdad," the military said in a statement. The statement said the public should be vigilant and warned specifically of intelligence that a stolen ambulance could be used as a car bomb. More than 100 people were killed in bomb attacks in northern Iraq this week. Suicide bombs and car bombs are hallmarks of al Qaeda in Iraq, the Sunni Arab militant group that shares a name and ideology if not organisational ties with Osama bin Laden's network blamed for the Sept. 11, 2001 attacks on the United States. Bin Laden's deputy, Ayman al-Zawahri, said in a taped recording the five-year U.S. war was a failure. "What the American invasion of Iraq has reached, today, after five years, is ... failure and defeat," he said in the message. "The American troops, if they leave will lose everything and if they stay will bleed to death." The authenticity of the recording could not be verified, but it sounded like Zawahiri and experts have judged similar recordings to be genuine in the past. (Editing by Matthew Jones)
United Nations special representative in Iraq Staffan de Mistura speaks during an interview with Reuters at the U.N. office in Baghdad April 18, 2008. REUTERS/Mohammed Ameen (IRAQ) ...