Twelve bodies were found in Baghdad's notorious Dura neighbourhood, while three corpses were recovered in the capital's Al-Shuala district and two more in the Shi'ite Kadimiyah neighbourhood.
"Of the 12 bodies found in Dura, two were found inside a foreign car and five next to the car," an official said.
Nine other people were killed across Iraq as violence continued unabated amid the power vacuum created by Iraq's lack of a national unity government four months after elections for the first post-Saddam Hussein parliament.
Hundreds of bodies have been found in the last two months since sectarian clashes erupted between Shi'ites and Sunni Arabs after the bombing of a Shi'ite shrine in the northern town of Samarra on February 22.
Sunni leaders claim most of the corpses have been identified as Sunni Arabs allegedly shot to death by Shi'ite-led interior ministry forces.
Insurgent attack
Meanwhile about 50 insurgents have mounted an attack on Iraqi forces in Baghdad, prompting US troops to provide support in a battle that lasted seven hours.
The guerrillas attacked Iraqi forces in the mostly Sunni Arab district of Adhamiya in northern Baghdad.
Five rebels were killed and one member of the Iraqi forces was wounded. There were no US casualties, the spokesman said.
"It was quite a battle. It lasted seven hours," he said. While insurgents mount such attacks in their strongholds in western Anbar province, they are rare in the Iraqi capital.
The attack raises fresh questions about security in the capital as Iraqi leaders struggle to form a unity government they hope can avert a sectarian civil war.
Leadership crisis
The latest violence comes after Iraqi leaders announced the scheduled parliament session would be cancelled after failure to solve a bitter dispute as to who would lead the next government.
But an optimistic foreign minister, Hoshyar Zebari, predicted the new government could be in place by the end of the month.
"I hope by the end of April, to be very realistic with you," Mr Zebari told the BBC. "We understand the impatience everybody is feeling, at home and abroad, among supporters of the new Iraq and we fully realise that time is of the essence."
Iraq's Sunni and Kurdish groups have rejected the choice for prime minister of the powerful Shi'ite majority, outgoing premier Ibrahim Jaafari, while the Shi'ites are opposing Sunni candidates for other posts.
The Sunni and Kurdish minorities accuse Jaafari of failing to curb sectarian violence.
In turn, the Shi'ite parties suspect the country's Sunni parties of having one foot in the political establishment and the other in the camp of Iraq's three-year insurgency that has targeted Shi'ites with bombings and shootings.
"The political crisis has deepened," Kurdish lawmaker Mahmoud
Othman told AFP. "The issues are not resolved. There is no agreement on Jaafari yet and the other problem is that the Shi'ite list has opposed the Sunni candidate for the post of parliament speaker."
The 275-member parliament has met only once since Iraq's December 15 election.
Baghdad's new ambassador to Washington, Samir Sumaidaie, told CNN yesterday a replacement for Jaafari was likely to be decided on in the coming days.
"A number of names have been mentioned. But leading amongst them is Ali al-Adib, who is from Jaafari's own party," Mr Sumaidaie said, adding that he "would stand for the same things that Mr Jaafari stands for."
The deadlock has coincided with a surge in violence that has raised fears the country is on the edge of an all-out civil war.