Thousands were already in the process of fleeing the suburb of Kingasani near the airport, where heavy fighting was reported between government troops and rebel forces, when the helicopter was shot down.

Earlier today, the government had broadcast an appeal asking soldiers in President Laurent Kabila's army now fighting for the rebels to lay down their arms.

It was not immediately clear how many people were killed, but Bernard Makenga, a local Congolese journalist who witnessed the incident, said he saw many bodies scattered about.

``The body of the helicopter was still burning on the ground,'' he said. People were crying and screaming.''

The helicopter was a green military aircraft flown by rebel pilots, a government commander said on condition of anonymity. It was unclear where the helicopter came from.

Rebels from a coalition force of ethnic Tutsi fighters and disenchanted members of Kabila's army had slipped into parts of the capital in recent days and launched an assault to take the airport. But yesterday, the government and allied Angolan, Zimbabwean and Namibian troops were firmly in control of the airport.

More than 1,000 prisoners had been captured in and around the capital, the government said.