Suicide bombers in a crowded Baghdad commercial district and Saddam Hussein's hometown of Tikrit killed at least 33 people Sunday as insurgents tried to turn a monthslong deadlock over forming a new Iraqi government to their advantage.

The latest violence began when bombers drove two cars packed with nearly 180 pounds (82 kilograms) of ammonium nitrate toward the gates of the Trade Bank of Iraq building in Baghdad and detonated the explosives after striking the surrounding blast walls, said Iraqi military spokesman Maj. Gen. Qassim al-Moussawi.

Vehicle debris are seen at blast site in Baghdad, capital of Iraq, June 20, 2010. At least 33 people were killed and 54 were wounded in two car bomb explosions in western Baghdad on Sunday. [Xinhua]

Al-Moussawi said at least 18 people were killed and 42 wounded. But three Iraqi police officials and a doctor at the Yarmouk hospital where many victims were taken put the toll at 28 killed and 57 wounded. Conflicting casualty tolls are common in the chaotic aftermath of bombings in Iraq.

Hours later, a man wearing an explosives vest blew himself up as police and onlookers responded to a roadside bomb apparently set as a trap in the northern city of Tikrit. At least five people were killed and 12 wounded in the late night attack, according to police and hospital officials.

The attacks added weight to warnings that insurgents would try to foment unrest as politicians squabble over forming a new government more than three months after inconclusive national elections.