By Mark Doyle
BBC World Affairs correspondent
The fighting in the Democratic Republic of Congo has been taking place in the heart of the elite business and embassy district of the capital, Kinshasa, on the shores of the River Congo.
Hundreds of Kinshasa residents have fled their homes
And it goes to the heart of the political rift in the country as well.
Jean-Pierre Bemba and the incumbent President Joseph Kabila are both former fighters who shot their way to positions of power.
Mr Bemba lost the nationwide presidential elections held last year against President Kabila by quite a large margin.
But he won the overwhelming support of voters in the capital, which reflected an ethnic split in the country.
Mr Bemba won the capital and the west; Mr Kabila won the east.
The fighting in Kinshasa has involved the use of small arms, machine guns and mortars.
The United Nations peacekeeping force which oversaw last year's elections, said it had deployed all its armoured cars, under fire, to shuttle endangered schoolchildren and civilians out of the centre of town.
Latest reports indicate that some of the positions earlier held by Mr Bemba's forces are now being patrolled by government troops.
Burning fires in Kinshasa can be seen from neighbouring Brazzaville
It is not clear which party started the latest fighting but a key issue at stake has been whether Mr Bemba's former militia forces would disarm, with some of them being integrated into a new coalition army.
The government said it was illegal for Mr Bemba to maintain a large armed force.
Mr Bemba's supporters said he needed bodyguards and he himself told the BBC that Mr Kabila's forces want to kill him.
The UN-backed elections last year were the first free polls in DR Congo for more than 40 years.
There has never been a tradition of democracy in the country but rather a strong culture, from colonial times through to the present day, of winner-takes-all.