An al-Qaida affiliate in Iraq has claimed responsibility for Monday's suicide bomb attacks on three Baghdad hotels that killed at least 36 people.
"The Islamic State of Iraq" group issued an Internet statement Wednesday calling the attacks the "fourth wave" of its bombing campaign in the Iraqi capital.
In Monday's bombings, suicide attackers blew up vehicles packed with explosives outside Baghdad's Sheraton, Babylon and Hamra hotels, which are popular with Western journalists and contractors.
The insurgent group says it also carried out three previous waves of coordinated vehicle bombings in Baghdad last year (in August, October and December). Those attacks on Iraqi government buildings killed almost 400 people.
In the latest blast in Baghdad, a suicide bomber blew up a car outside a police crime lab Tuesday, killing at least 22 people and wounding 80.
There has been no claim of responsibility for the crime-lab attack. Officials say many of those killed or wounded were police officers.
U.S. Secretary of State Hillary Clinton condemned the latest attacks and said those who committed them will not succeed in derailing Iraq's efforts to build a future of peace and security.