Iraq's main Sunni Arab political alliance has rejected the partial results of last week's parliamentary election in Baghdad province.
The Iraqi Accord Front had earlier praised the election
The Iraqi Accord Front threatened to block the creation of a new government if the result was not changed.
Later on Tuesday, Iraqi President Jalal Talabani called for a new government that includes all ethnic, religious and political groups.
He said Iraq could not "be governed by a majority that ignores the minority".
The three main Sunni Arab parties that make up the Iraqi Accord Front said the election in Baghdad had been rigged and demanded that Iraq's electoral commission order a new vote.
"We reject these results announced by the commission," said Adnan al-Dulaimi, one of the leaders of the front.
"If the commission does not take steps to restore justice to other lists, we will demand a new election be held."
Tarik al-Hashimi, secretary general of the Iraqi Islamic Party, warned the commission "not to play with fire".
"We will not remain with our arms crossed and we will not abandon those who voted for us," said Khalaf al-Ulayyan, leader of the third party in the bloc, the Iraqi National Dialogue Council.
Sunni Arabs appeared to have voted in large numbers last Thursday, having boycotted the election for the transitional administration in January.
Shias and Kurds dominant
The Iraqi Accord Front came second with 18.6% of the vote in Baghdad Province, partial results from 89% of the ballot boxes showed.
IRAQ ELECTION FACTS
275-seat National Assembly will have four-year term
18 provinces are taken as separate constituencies
230 seats allocated according to population
45 seats distributed to parties whose ethnic, religious or political support is spread over more than one province
15 million eligible voter
One third of candidates in each party must be women
The Shia-led United Iraqi Alliance won 58% of the vote in Iraq's largest province, where 2,161 candidates ran for 59 of the Council of Representatives' 275 seats.
Former Prime Minister Iyad Allawi's secular Iraqi National List came third.
The election commission also announced that the United Iraqi Alliance was ahead in Basra and eight other southern provinces, and that the Kurdistan Alliance was leading in four northern provinces, including oil-rich Tamim.
In the four remaining provinces, where the population of Sunni Arabs is largest, the Iraqi Accord Front came top.
The front won 73% of the vote in Anbar Province, 36% in Nineveh, 33% in Salahuddin, 36% in Diyala.
The BBC's Middle East analyst, Roger Hardy, says the results in Baghdad will be bad news for both Mr Allawi and the Iraqi Accord Front, which wants to increase Sunni Arab representation in a parliament currently dominated by Shia and Kurdish parties.
To judge from the votes counted so far, the Shia alliance is likely to retain its dominant position, our correspondent says.
The election commission has said the final results will not be announced until early next month, due to an investigation into complaints of irregularities.
Farid Ayar, an election official, said the commission had received 1,000 complaints, of which 20 were described as "very serious".
"We are studying all of them, we have two or three committees studying them," he said.
"They are serious and they may change the results, but I don't think the complaints will make a big change in the overall result."
President Talabani, one of the leaders of the Kurdistan Alliance, has said he wants to see a broad-based government regardless of the election result.
Mr Talabani wants Iraq to focus on reconstruction and security
"We want a government linking everyone, Arabs be they Shias or Sunnis, Kurds and Turkomans," he told reporters.
Mr Talabani played down the Sunni complaints and said the election had been carried out fairly.
"Some objections are rational and others are not. It is up to the electoral commission to separate them," he said.
"[The election] strengthened Iraq's standing in the world and proved that the Iraqis are capable of practising democracy."
The president said the new government would have to focus on Iraq's reconstruction and the security situation.
Meanwhile, a Jordanian working as a driver at his country's embassy in Baghdad has been kidnapped.
Unidentified gunmen abducted Mahmoud Sulaiman in the capital's southern al-Saida district shortly after he left for work.
Jordan's prime minister, Maaruf al-Bakhit, has vowed that his government will exert every possible effort to secure Mr Sulaiman's release.
A number of Arab diplomats and embassy workers have been kidnapped this year.
The Egyptian ambassador-designate, two Algerian diplomats, and two Moroccan embassy workers have all been abducted and are believed to have been killed.