The central African nation of Burundi was plunged deeper into a political crisis Wednesday after the three government ministers from the main Tutsi party resigned.

The walkout by the Uprona party members upsets an increasingly delicate power-sharing arrangement between Burundi's majority Hutu and minority Tutsi communities, who are still struggling to reconcile after decades of conflict.

The U.S. military's partnership with France in Africa is "indispensable" in the fight against extremist groups in the Sahel region, French Defense Minister Jean-Yves Le Drian said on Friday.

During a visit to Washington, Le Drian said "terrorist groups are circulating across the whole Sahara-Sahel area and terrorist acts could put our own security at risk."

The U.S. military flew Thursday the first batch of troops from Burundi to join an African Union force to restore security in the Central African Republic, the army said.

"The first U.S. aircraft to transport the Burundian contingent to Bangui arrived this morning," said Lieutenant-Colonel Potien Hakizimana, commander of the 850-strong Burundi battalion going to CAR.

Supporters of rival political parties in Burundi clashed in street battles that left five people seriously wounded, government officials said Monday, the latest tensions in the small central African nation.

Youths from the opposition MSD were out running Sunday singing songs supporting their party when they encountered the Imbonerakure youth wing of the ruling CNDD-FDD, leading to fighting, said Leopold Ndayisaba, administrator of Gihanga, a small town some 20 kilometers (15 miles) north of the capital Bjumbura.

Burundi and Uganda said Thursday they had beefed up security after the Shebab's deadly Nairobi mall attack amid fears the extremists would now strike Kenya's military partners in Somalia.

Kenya, Uganda and Burundi contribute most of the 17,700 soldiers in the African Union's AMISOM force battling the Shebab in Somalia.

A Burundi ex-rebel chief who returned from the bush in a bid to re-enter politics dismissed Thursday allegations he ordered the massacre of refugees nine years ago.

Refugees in Burundi from Democratic Republic of Congo have lodged a complaint against Agathon Rwasa for his alleged role in a 2004 refugee camp massacre of some 160 Congolese Tutsis in Gatumba, to the west of the Burundi capital Bujumbura.

Burundi's veteran rebel leader Agathon Rwasa resurfaced Tuesday after three years in the bush, but police stopped him from addressing a crowd of supporters who came to welcome him.

"Three years ago, in the wake of the dispute over the elections, I had to leave those close to me in order to save my skin," Rwasa told reporters at a villa in the capital Bujumbura.

A cholera epidemic in Burundi, the longest in the small central African country's history, has killed at least 17 people in 10 months, a top health official told Agence France Presse Monday.

"Burundi has been affected since last October by a cholera epidemic," said Liboire Ngirigi, director general of public health.

Regional leaders meeting to end the chronic violence in the east of the Democratic Republic of Congo failed to find a breakthrough, with Rwanda saying only that "steady progress" had been made.

DR Congo President Joseph Kabila and his Rwandan counterpart Paul Kagame met Monday at a lakeside resort hosted by Ugandan President Yoweri Museveni, and also attended by the leaders of Burundi, South Sudan and Tanzania.

Villagers in northeast Burundi hacked to death a woman accused of witchcraft and five members of her family, including a baby and two other children, local authorities said Sunday.

On Saturday "a group of people attacked the home of an old woman called Marthe Kabatesi in the Bwambarangwe district," said Reverien Nzigamasabo, governor of Kirundo province where the killings took place.