Al-Qaida in Iraq is the most likely suspect behind massive truck bombings targeting major government institutions in Baghdad.
But the prime minister and other Shiite politicians also linked Saddam Hussein loyalists to the attacks, an allegation that may indicate a more political tilt to the violence ahead of January's parliamentary elections.
Analysts and Iraqi lawmakers said the steadily escalating attacks are clearly aimed at undermining the government and Iraqi security forces at a sensitive time and warned that political rhetoric is stoking the tensions.
No group claimed responsibility for Wednesday's truck bombings at the foreign and finance ministries, but the US military said they bore the hallmarks of al-Qaida, which is known for its high-profile vehicle bombs and simultaneous suicide attacks.
Prime Minister Nouri al-Maliki, however, added a twist, blaming an alliance of al-Qaida and supporters of Saddam's Baath party for the attacks.