Gunshots sounded and street brawls broke out Tuesday among a crowd rallying for the runner-up in Congo's landmark presidential vote as he pursued a court challenge of his loss. Part of the country's supreme court caught fire in the melee.

The violence underlines the tensions in a country balanced precariously between dictatorship and democracy, war and peace. It comes less than a week after interim President Joseph Kabila was declared winner of a runoff vote to choose the Central African country's first democratically elected leader in more than four decades.

A first-round vote was marred by deadly clashes in the capital between the forces of Kabila and those of runner-up Jean-Pierre Bemba. The two sides fought again when early results of the runoff pointed to a Kabila victory. But Bemba said he would keep his challenge peaceful. He has said systematic cheating tainted the vote.

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The latest election-related civil unrest in the capital, Kinshasa, began as about 200 Bemba supporters massed outside the court building as proceedings on his motion got under way. Fights broke out in the angry crowd.

Sporadic gunfire was heard for about 45 minutes as U.N. peacekeepers sped to the scene in armored vehicles, then fired in the air to disperse the crowd. About 17,500 U.N. peacekeepers — its largest force in the world — are in Congo to maintain calm as the country transitions to democracy.

Officials said gunmen in the crowd had fired on security forces, but no injuries were immediately reported.

"Armed men were mixed in with the civilians and shot at the police," Interior Minister Denis Kalume said.

At least two cars were set ablaze in the fighting and several offices in the two-story court building caught fire, along with furniture and documents. U.N. soldiers evacuated the building and firefighters worked through the afternoon to contain the flames.

A spokesman for Bemba's party, Moise Musangana, said it "condemns these acts of vandalism," adding that Bemba would have no reason to try to derail the court proceedings.

Government officials said they would evaluate the damage Wednesday before deciding how to proceed with the trial.

Meanwhile, officials in neighboring Republic of Congo said more than 2,000 people have arrived there in the past four days after fleeing election-related fighting in Congo. Many of the refugees were described as supporters of Kabila who were running from violent partisans of Bemba.

In Kinshasa, Interior Minister Kalume said he could only confirm that about 30 families — a figure more likely to be in the hundreds than the thousands — had fled as a result of ethnic fighting in the town of Bolobo. He said he did not know of any political disputes that sparked the violence.

Bemba, who ruled his own private fiefdom in northern Congo during the 1998-2002 civil war and became one of four vice presidents in a postwar, transitional government, garnered overwhelming support in Kinshasa and western Congo but only 42 percent of the overall vote, according to the Independent Electoral Commission. President Joseph Kabila won 58 percent.

A coalition of some 50 parties supporting Bemba claim that votes counted at ballot stations Oct. 29, the day of the runoff, do not conform with the published results. The process was generally deemed fair by international election monitors.

Rich in cobalt, diamonds, copper, gold and other minerals, Congo gained independence from Belgium in 1960 and was ruled for 32 years by Mobutu Sese Seko, a dictator who plundered the wealth, pocketing billions and doing little to develop the giant nation. Kabila's father, Laurent, helped depose Mobutu, but was then assassinated, leaving his son in power.

The younger Kabila signed peace accords to end Congo's war, which drew in the armies of at least six countries, and established the national-unity government he heads.

The new president will have to establish a unified army and regain control over lawless borderlands in the east, thousands of miles from Kinshasa, where rebels and militiamen accused of raping and pillaging residents collect their own taxes. Aid groups estimate Congo's wars and ongoing violence has left 4 million people dead, most through strife-related hunger and disease.

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