Zairian soldiers attempting to hijack a car shot and killed two Rwandan refugees, heightening tensions in the squalid camps near Goma, U.N. officials said Tuesday.

It was the latest incident of thievery, thuggery and brutality by Zairian troops, whose conduct has been condemned by the United Nations and their country's prime minister.Panos Moumtzis, spokesman for the U.N. High Commissioner for Refugees, said four soldiers tried to hijack a refugee's car Monday in one of the camps north of Goma.

The driver resisted, Moumtzis said, and a crowd quickly gathered and began pelting the soldiers with stones. He said the soldiers fired in the air, then leveled their weapons when the crowd failed to disperse.

Moumtzis said two refugees in the crowd were killed and four injured.

Thousands of residents and refugees rioted in this border town in eastern Zaire last week after a currency dealer was shot to death by a soldier demanding money.

Prime Minister Leon Kengo wa Dondo later acknowledged that some of the 400 troops sent to Goma to help with the Rwandan refugee crisis had acted irresponsibly. He said the guilty would be court-martialed.

Kengo also said all of the soldiers would be withdrawn and replaced, but no action has been taken.