The UN peacekeeping mission in the Central African Republic on Monday revised a death toll for weekend clashes in the heart of the nation down to six.

"The total number of people killed was six," MINUSCA force chief Herve Verhoosel said in a statement, adding that an investigation into the deadly violence was under way.

A police source told AFP on Sunday that at least 20 people had been killed and several more injured since Friday in clashes pitting ex-Seleka rebel fighters against the anti-Balaka militia.

"Ex-Seleka" is the term used for remnants of the supposedly disbanded alliance of mainly-Muslim armed groups which seized power in the CAR in late 2013.

The groups fought vigilantes from the mainly Christian anti-Balaka (machete) militia before being chased from the capital the following year.

On September 16, in Ndomete in the centre of the country, "ex-Seleka members clashes with the anti-Balaka", MINUSCA said, adding that peacekeepers "dispersed fighters from both sides."

"These clashes left four people dead," the peacekeeping force said.

Two other people died in Kaga Bandoro some 10 kilometres (six miles) to the north, after the houses of several peacekeepers were looted, MINUSCA said.

In a statement on Sunday, the UN mission said it had sent troop reinforcements to Kaga Bandoro and the village of Ndomete, which was particularly affected by the violence, "to prevent any deterioration of the situation."

Kaga Bandoro is the fiefdom of the Popular Front for the Renaissance of the Central African Republic (FPRC), an ex-Seleka splinter group.

It is led by Noureddine Adam, who faces international sanctions for his alleged role in intercommunal killings in 2013 and 2014.

Violence in CAR over recent years has claimed thousands of lives and prompted hundreds of thousands to flee their homes, even if the presence of French and UN troops has gone some way to improving security.

-AFP