A homicide bomber killed 32 mourners and wounded dozens at a funeral for the nephew of a Shiite politician, one of several attacks Wednesday across Iraq that killed a total of 53 people — making it the deadliest day since the Dec. 15 elections.

The increased violence came as Iraq's three major political parties were close to forming a coalition government that would include Shiites, Sunni Arabs and Kurds, according to a Shiite politician.

Iraq's election commission also planned to release the results of its investigation into almost 2,000 complaints stemming from last month's parliamentary elections, commission member Safwat Rashid said.

More than 100 mourners were standing in a cemetery in Muqdadiyah, about 60 miles north of Baghdad, for the burial of a nephew of Ahmed al-Bakka when the bomber struck, the Diyala provincial police said. The cemetery was strewn with body parts and the tombstones were stained with blood.

At least 32 people were killed and 42 wounded, said Dr. Firas al-Nida of the Muqdadiyah hospital.

Al-Bakka had survived an assassination attempt Tuesday that killed his nephew. Al-Bakka is the head of the local Dawa party, led by Prime Minister Ibrahim al-Jaafari and a main partner in the country's largest Shiite political coalition, the United Iraqi Alliance.

Shiites have been targeted by extremist Sunni groups such as Al Qaeda in Iraq, led by Jordanian-born terrorist mastermind Abu Musab al-Zarqawi.

A partner in the largest Sunni Arab political party denounced the attack.

"The Islamic Party condemns such ugly acts that are aimed at dividing the country," said Nassir al-Ani. "The perpetrators want to cause divisions and hinder the political process in Iraq, but they will fail and we will establish a national unity government."

Insurgents attacked a convoy of 60 tanker trucks with rocket-propelled grenades and machine guns, destroying three of the tankers and damaging 15 others, said police Lt. Abdul Zahra Qassim. Three Iraqi army vehicles, which had been guarding the convoy, were also destroyed in the attack about 25 miles north of Baghdad, police said.

Tanker truck drivers had stopped transporting gasoline from Iraq's largest refinery in Beiji on Dec. 18 because of security concerns. The drivers began carrying fuel again this week after being promised increased security.

In other violence Wednesday, a car bomb exploded near an outdoor market in Baghdad's southern Dora district, killing seven people and wounding 15, police said.

The bomb, which damaged several shops and nearby vehicles, targeted a police patrol near the market at the time, said police Capt. Firras Giti.

Another car bomb in northern Baghdad killed three civilians and a policeman, and wounded 13, said Maj. Mosa Abdelkareem.

A roadside bomb targeting a U.S. patrol in Kirkuk, 180 miles north of Baghdad, hit a civilian car instead, killing three passengers, said police Col. Polla Mohammed.

In the capital, gunmen in separate incidents killed a former army captain and fired on the car of an oil ministry employee, killing the man and his son, police said.

Gunmen in Mosul, 225 miles northwest of Baghdad, attacked the political offices of the Patriotic Union of Kurdistan, killing a civilian, Dr. Bahaldin al-Bakri said. A roadside bomb in Baqouba killed a woman, the Diyala police said.

In Aziziyah, 35 miles southeast of Baghdad, gunmen fired on a police patrol, killing one policeman, Hadi al-Itabi of the Kut morgue said. Gunmen in Ramadi killed a professor at Anbar University, according to Mohammed al-Ani of the Ramadi hospital.

Roadblocks went up across Baghdad as police searched for the sister of Interior Minister Bayan Jabr, who was kidnapped Tuesday. Gunmen killed one of her bodyguards and seriously wounded another in the abduction.

A description of the suspects' car had been distributed to all checkpoints, said Lt. Thair Mahmoud.

Jabr is a member of the Supreme Council of the Islamic Revolution in Iraq, the country's largest Shiite party, and was formerly a senior official of the Badr Brigade, a militia that belongs to SCIRI. He has recently been the focus of criticism over allegations of torture and abuse of prisoners at Interior Ministry jails. Many of the those abused were Sunnis, the group thought to fuel the insurgency.

The three tickets — the Shiite United Iraqi Alliance, the Sunni Arab Iraqi Accordance Front and the Kurdish coalition — were working on a coalition government, an Alliance official said Wednesday, and were discussing a nominee for prime minister.

"We can say that the (three parties) are close to forming a new government," said Ridha Jawad Taqi, a member of SCIRI, which is coalition partner in the United Iraqi Alliance. "Meetings between the tickets will be resumed after announcing the final results of the elections."

An international monitoring team this week began to review results from last month's elections, including some of the hundreds of complaints filed. A member of Iraq's election commission said final results won't be announced until the international review was completed, meaning results might be delayed until mid-January.

Meanwhile, the Independent Electoral Commission of Iraq said it had completed its investigation of 1,980 complaints, including 50 that were considered serious enough to alter results in some districts, an election official said.

The separate international team agreed to review Iraq's elections after protests by Sunni Arab and secular Shiite groups that the polls were tainted with fraud.

Preliminary results give the governing United Iraqi Alliance a big lead, but one that would still require forming a coalition with other groups.