BAGHDAD, Iraq (AP) — A U.S. military patrol and Iraqi police discovered 23 bodies — many of them handcuffed and strangled — in various parts of Baghdad, authorities said Wednesday, while bombings, gunfire and other violence claimed at least seven other lives.

Among the reported deaths was a U.S. soldier who was killed by a roadside bomb Tuesday near the northwestern city of Tal Afar. Four other soldiers were wounded in the attack, the military said.

The unrelenting violence came amid a deepening political stalemate among Iraqi ethnic and religious factions that threatens the creation of a unity government U.S. officials hope can stabilize the country so foreign forces can start going home this summer. Underlining U.S. concerns, the ambassador held talks with a top Shiite leader Tuesday.

An American patrol found 18 of the bodies — all males — in an abandoned minibus Tuesday night on a road between two notorious west Baghdad neighborhoods. Most bore marks indicating they were hanged or strangled, and two were shot to death, said Dr. Mohanad Jawad at Yarmouk Hospital, where the bodies were lined up on stretchers in the morgue. Police believed at least two of them were foreign Arabs.

Police found the bodies of four other handcuffed and strangled men in an open field in east Baghdad on Wednesday. Another body, shot in the head, was found near a shop in an eastern suburb.

The gruesome discoveries followed a surge of sectarian violence unleashed by the Feb. 22 bombing of a sacred Shiite shrine in the central city of Samarra and reprisal attacks against Sunni mosques and clerics. Sectarian killing has diminished in recent days, but other attacks have increased, the Defense Ministry reported Tuesday.

A string of explosions Wednesday killed at least four people — including two young boys — in the capital, police said.

One bomb hidden under a parked car near the University of Technology detonated as police from the interior minister's protection force were driving through central Baghdad, killing two officers, police said. Five other people, including a policemen, were injured in the blast. The minister was not in the convoy at the time, police said.

Another bomb missed an American convoy on the northern outskirts of Baghdad and killed two Iraqi boys who were selling gasoline by the roadside, police said. He estimated their age at 10 or 11.

At midday, an Iraqi patrol saw four gunmen pull a man from the trunk of a car and shoot him to death in west Baghdad, police reported. They said the patrol tried to intercede, but the gunmen fired at them and fled.

The inability to agree on a broad-based government after December parliamentary elections is threatening to crush American hopes of beginning a troop pullout this summer. Washington policy holds that such a unity government would inspire sufficient loyalty from all parties to enable it to fight the raging insurgency by itself.

Prime Minister Ibrahim al-Jaafari declared Tuesday he would not be "blackmailed" into abandoning his campaign for a second term despite opposition from Sunni, Kurdish and some secular Shiite leaders who have vowed not to cooperate with him.

Al-Jaafari's Shiite United Iraqi Alliance, which has the largest bloc of lawmakers, asked President Jalal Talabani on Tuesday to delay summoning parliament into session until the dispute is resolved.

Alliance members are themselves divided over al-Jaafari, who won the Shiite nomination by a single vote last month, with the backing of radical anti-American cleric Muqtada al-Sadr.

Talabani, a Kurd, had hoped to bring the dispute to a head by convening parliament on Sunday. Under the constitution, parliament is supposed to elect a new president within 15 days of its first meeting. It then has 15 more days to approve the prime minister, and 30 days after that to vote on his Cabinet.

To convene the session, Talabani needs the approval of his two vice presidents, Abdil Abdul-Mahdi, a Shiite, and Ghazi al-Yawer, a Sunni. Abdul-Mahdi, al-Jaafari's main rival for the Shiite nomination, has declined to sign, for now.

An evening meeting Tuesday between the Kurdish faction in parliament and the Shiite Alliance failed to break the impasse.

Representatives of the main political blocs planned to meet at Talabani's office Thursday to discuss the standoff and decide a new date for parliament to meet.

Underscoring Washington's concerns over the deteriorating political situation, U.S. Ambassador Zalmay Khalilzad held a meeting with Abdul-Aziz al-Hakim, head of the powerful Shiite Supreme Council for the Islamic Revolution in Iraq, one of the two dominant parties in the Shiite coalition.

The two met at al-Hakim's Baghdad home Tuesday to discuss "the current political situation concerning the formation of a new government and developments related to the alliance's candidate to head the Cabinet," the SCIRI Web site reported with an accompanying photo of the session. The U.S. Embassy did not immediately respond to a request for further information.

In an interview published Tuesday in the Los Angeles Times, Khalilzad said the 2003 U.S. ouster of Saddam Hussein had opened a "Pandora's box" that could see the violence and turmoil now gripping Iraq turn into an all-out regional war if American troops are withdrawn too quickly.

But narrowing the differences among Iraq's Shiites, Sunnis and Kurds has become an increasingly difficult task in the aftermath of the Feb. 22 bombing of the golden domed Shiite Askariya shrine.

Sunni politicians have accused the Mahdi Army, the Shiite militia loyal to firebrand cleric al-Sadr, of launching many of the revenge attacks against Sunni mosques and clerics with the blessing of the Shiite-controlled government security apparatus — charges denied by the government.

In a report Tuesday, U.N. Secretary-General Kofi Annan said U.S.-led coalition forces and Iraq's authorities may be violating international law by arbitrarily detaining thousands of people.

The report, which studied the situation in Iraq for the last three months, said its prison system remains a major concern and lamented that an investigation into allegations of torture in Interior Ministry jails had not been made public as promised.

As political negotiations stalled, the violence raged on.

A former brigadier in Saddam Hussein's army was shot and killed Wednesday in western Baghdad, police said.

A bomb exploded at the Basra headquarters of Iraq's South Oil Co., causing minor damage but no casualties. Crude production and exports were not affected, said Jabar Luaibi, the company's director general.

Also Wednesday, an Iraqi civilian was killed in a collision with a U.S. Bradley Fighting vehicle after failing to head warning signs to stop, the military said in a statement.

The death of the U.S. soldier that was reported Wednesday brought to at least 2,302 the number of U.S. military members who have died since the beginning of the war in March 2003, according to an Associated Press count. The figure includes seven military civilians.

Bombings, mortar blasts and gunfire killed 19 people Tuesday, and police also reported finding four bullet-riddled bodies — two with their eyes gouged out.