France has sent soldiers to Central African Republic to secure the airport of the capital Bangui, a diplomatic source said, after rebel forces entered the north of the city.

"A company of troops has been sent to secure the airport. The airport is now secure," said the source on Saturday. "We have asked our citizens to remain at home. For the time being, there is nothing to be worried about. There is no direct threat to our citizens at the moment."

A second diplomatic source said that Paris had requested an urgent meeting of the UN Security Council to discuss a

solution to the crisis in the landlocked former French colony at the heart of Africa.

Nelson Ndjadder, a spokesman for the Seleka rebel coalition, said earlier on Saturday that his fighters entered the capital and were heading to the presidential palace in the centre of town.

He also said they had shot down a government military helicopter which had been attacking their forces since Friday.

The Seleka rebels resumed hostilities this week in the mineral-rich former French colony, vowing to topple

President Francois Bozize whom it accuses of breaking a January peace agreement to integrate its fighters into the army.

Speaking to Al Jazeera from Bangui, Central African Republic's Deputy Prime Minister Parfait Mbaye, said the rebel advance "should be condemned by the African union".

"The coup d’etat attempt by Seleka rebels is still ongoing. Fighting is now taking place on the outskirts of Bangui. We can only condemn this attempt to take power by force... We are very sorry to see what is happening in our country."

The rebels are said to have driven back government forces and taken control of the neighbourhood around Bozize's private residence. Officials said Bozize was in the presidential palace in the town centre.

Speaking to Al Jazeera from Bangui, Sylvain Groulx of Doctors without Borders, said the fighting has not yet reached to centre of the capital.

"We are about two-to-three kilometres from the centre of Bangui and we cannot hear any shooting but we have heard the same information that a group of rebels has entered the capital," Groulx said.

"There has been some fighting in different places in and around Bangui throughout the day," Groulx added.

"It seems that the rebels have taken control of a town called bouali where there is a hydro-electric dam, the main power source for Bangui. All the power in the capital was cut. The hospitals we are supporting have been provided with fuel for generators."

South African troops

The violence is the latest in a series of rebel incursions, clashes and coups that have plagued the landlocked nation in the heart of Africa since its independence from France in 1960.

Pretoria has sent some 400 soldiers to train Bozize's army, joining hundreds of peacekeepers from the Central African regional bloc.

Regional peacekeeping sources said the South Africans had fought alongside the Central African Republic's army.

"I don't understand why we are making such a big deal about the presence of South African troops," Mbaye told Al Jazeera.

"We have an agreement with South Africa, a member of the African union and they are currently helping Central African forces. We salute South African forces and the South African people."

State radio announced late on Friday that South Africa would boost its troop presence after Bozize met his South African counterpart Jacob Zuma in Pretoria.

Captain Zamo Sithole, senior operations communications officer at South Africa's National Defence Force said: "We are there in the CAR to protect our properties there, and our troops there."

A South African Defence Ministry spokesman declined to comment.