Assailants in speeding cars gunned down a police commando as he was leaving his house in south Baghdad Thursday, and drive-by shooters killed a lawyer as she got out of a taxi in the southern city of Basra, police said.

Bombings and other attacks in the capital killed a policeman and wounded a dozen Iraqis.

The U.S. military also reported the death Thursday of an American soldier in Fallujah, west of Baghdad in the volatile province of Anbar. The soldier of the 9th Naval Construction Regiment died Tuesday from wounds sustained in fighting, the military said.

Talks to form a new government remained stalled, meanwhile, as Iraqi politicians canceled their multiparty meetings Wednesday, saying they needed time to consult with their political blocs over the critical issue of what powers the next prime minister would have over security issues.

It was the second time this week political leaders shunned a session meant to overcome the government stalemate that is in its sixth week.

The major stumbling block in the negotiations is the nomination of Prime Minister Ibrahim al-Jaafari, a Shiite, for a second term. Al-Jaafari faces deep opposition from Kurdish and Sunni politicians. On behalf of President Bush, U.S. Ambassador Zalmay Khalilzad has asked other top Shiite leaders for help in persuading al-Jaafari to step aside.

While al-Jaafari was not known to have formally responded to the U.S. request, he said in an interview Wednesday that there was "concern among the Iraqi people that the democratic process is being threatened."

Speaking with The New York Times, he implied the threat arose from what he viewed as the involvement of "some American figures (who) have made statements that interfere with the results of the democratic process."

The United States has been pushing Iraq to speed the formation of a unity government, seen as the best option to subdue the violence gripping several Iraqi cities — and to allow for the start of a U.S. troop withdrawal this summer.

There has been no breakthrough in the government deadlock since results of the Dec. 15 parliamentary elections were certified Feb. 12. Parliament has met only once, in a 40-minute session so new members could be sworn in.

The March 16 meeting, however, set in motion a 60-day clock for electing a president, approving the prime minister and signing off on his cabinet.

In Thursday's violence, a suicide car bomber rammed a police convoy in west Baghdad's Yarmouk neighborhood, killing one police commando and wounding three others. Two civilians also were hurt. Elsewhere, roadside bombs hit a minibus and a police patrol, wounding at least five civilians, and gunmen wounded at least two policemen, authorities said.

Police discovered the body of a man who had been strangled in Baghdad's northern neighborhood of Hurriyah, likely yet another in the capital's underground battle of revenge killings between Sunni and Shiite Muslims.

Hundreds of Iraqis have been killed in sectarian violence and by death squads operating inside the Shiite-dominated ministry since the Feb. 22 bombing of an important Shiite shrine in Samarra set off a wave of revenge attacks. Usually, the victims are killed in secret, their bodies discovered hours or days later.

Insurgents also blew up a pipeline transporting oil from the northern city of Kirkuk to the Beiji refinery on Thursday, an engineer in the region said.

On Wednesday, gunmen stormed a Baghdad business for the third time in as many days, this time lining 14 employees against the wall and shooting them all. Eight were killed, and at least 26 others were reported dead in violence elsewhere.