BAGHDAD: Al-Qaida's umbrella group in Iraq claimed responsibility Thursday for the coordinated Baghdad bombings this week that killed 127 people and wounded more than 500, warning of more strikes against the Iraqi government.

The group, known as the Islamic State of Iraq, said in a statement posted on the Internet that the strikes in the Iraqi capital targeted the "bastions of evil and dens of apostates."

It also warned the group is "determined to uproot the pillars of this government" in Iraq and said "the list of targets has no end."

The blasts Tuesday were the third major strike against government sites in the Iraqi capital since August, raising serious questions about the abilities of Iraqi security forces ahead of next's year national elections and the withdrawal of U.S. combat troops.

Prime Minister Nouri al-Maliki was expected to attend a special parliamentary session Thursday where lawmakers demanded Iraq's top security officials appear to answer questions over security lapses that allowed the attacks.

Al-Qaida's claim gave renewed emphasis to U.S. military warnings that insurgents would likely continue high-profile attacks in an attempt to destabilize the Iraqi government in advance of the March 7 parliamentary elections.

Al-Maliki, who has been under fire in recent days from lawmakers and others to address security lapses, signaled the beginning of a possible security shake up late Wednesday after replacing the military chief in charge of Baghdad security.

It was unclear whether al-Maliki might take further action, or whether his interior and defense ministers would even attend the special session. Both ministers have refused to attend two other sessions called after suicide bombings against government buildings on Aug. 19 and Oct. 25. More than 250 were killed in those attacks.

Iraq has claimed al-Qaida and loyalists of Saddam Hussein's Baath party operating from Syria were behind the August and October as well as the most recent bombings. Relations between the two countries soured after Baghdad accused Syria of harboring senior Baathists who masterminded the attacks. Syria has denied it.