U.S. troops fought insurgents in a central Baghdad (search) neighborhood Tuesday and a Turkish businessman held hostage for almost two months was released after his family reportedly paid a ransom.

Meanwhile, Iraq's (search) Independent Electoral Commission said it received at least six complaints so far from political groups challenging the results of Jan. 30 elections. Parties have until Wednesday to file grievances against the landmark vote.

"We received six complaints until now, but there other complaints sent by e-mail and we haven't retrieved them yet," said election official Adel al-Lami.

In Baghdad, U.S. troops and gunmen exchanged automatic weapons fire in the area around Baghdad's notorious Haifa Street (search) on Tuesday, police and witnesses said.

The gunbattle lasted between 10 to 15 minutes, and U.S. troops sealed off the area afterward, said policeman Salam Mohammed. No casualties were reported.

Kahraman Sadikoglu, president of the Istanbul-based Tuzla Shipyard, was released late Monday, and flown to Baghdad after spending the evening at a British base in southern Iraq, a Foreign Ministry official said. He was scheduled to return to Turkey later Tuesday through Jordan.

The ministry official did not give further details, but newspaper reports said Sadikoglu was released after his family paid hundreds of thousands of dollars in ransom.

Sadikoglu was apparently abducted after leaving the southern city of Basra on Dec. 16.

His kidnappers later sent a video to a Turkish media organization in Iraq in which he appeared alongside a weeping employee, saying they were being treated well by their captors.

In the tape, Sadikoglu said he was working for the United Nations and the Iraqi government on a project clearing harbors of sunken ships.

Sabah newspaper said his captors initially demanded $25 million in ransom, but later lowered the demand to a few hundred thousand dollars.

Insurgents in Iraq have kidnapped more than 180 foreigners during a bloody campaign to force U.S.-led coalition troops to leave Iraq. Many have been killed; others remain in captivity, have been released for ransom, freed or have escaped.

In Baqouba, the deputy governor of a volatile province north of Baghdad escaped an apparent assassination attempt Tuesday after a suicide bomber rammed his car into a government convoy, police said.

The bomber died, but no other casualties were reported in the insurgent attack in Khalis, 50 miles north of the Iraqi capital, said police Lt. Ali Hussein.

The violence comes days after election officials announced the results of the Jan. 30 elections.

A Shiite Muslim clergy-backed slate won 48 percent of the votes and 140 of the 275 National Assembly seats, according to results released Sunday in Baghdad. A Kurdish ticket got 26 percent and 75 seats, while a secular Shiite party won 40 seats. Nine parties divided the remaining 20 seats.

The provisional results have yet to be certified by the election commission pending challenges and complaints.

On Tuesday, al-Lami, the commission official, said at least six complaints had been filed so far.

One complaint came from a group that lost the election, requesting a recount, al-Lami said. He added that a number of complaints are already being handled by the committee responsible for counting ballots.

After the commission investigates the complaints, the results will be certified and the commission will announce the exact number of seats each winner will take.

Before the results were announced, the commission received 359 complaints from inside and outside Iraq, not only political groups but also from tribal congregations and citizens who weren't able to vote.

Allegations of voting irregularities, especially around the tense northern city of Mosul, have complicated the count. Some leading Sunni Arab and Christian politicians alleged that thousands of their supporters were denied the right to vote.

Election officials blamed the problems in the Mosul area on security, which prevented fewer than a third of the planned 330 polling centers from opening. Gunmen seized some ballot boxes, officials said.