The death toll in the Central African Republic has risen to nearly 70 in four days, a peacekeeping officer says, following a surge of sectarian violence in the crisis-hit country.

The deaths have all happened since Monday near the central town of Bambari, which has seen a series of bloody clashes between mainly Muslim ex-Seleka rebels and Christian militias.

“Nearly 70 people have been killed since Monday in violence in Bambari and the nearby villages, at least a hundred people have been injured and around 150 houses have been burnt down,” a member of the African peacekeeping force MISCA said on Thursday, requesting anonymity.

“The death toll is still provisional because we have not been able to access all of the area,” he added.

Earlier in the week the same officer said that many of those who had been killed had been shot or stabbed to death, and that clashes “appear to be co-ordinated attacks by armed groups,” both from Christian and Muslim militias.

“It is unacceptable that the authorities are not reacting to what is happening in Bambari, innocent people are being massacred.”

There has been a surge in violence since the killing of 17 Muslims at a camp in the region on Monday by gunmen claiming to be from a mostly Christian militia called the anti-balaka.

A spokesman from the militia denied that they were behind the attack, but the massacre led to an outbreak of tit-for-tat violence and caused many civilians to flee.

In Bangui, some inhabitants were calling on Thursday for a three-day period of mourning for the victims.

“I will observe it, and will be putting a piece of black cloth on my shirt. It is unacceptable that the authorities are not reacting to what is happening in Bambari, innocent people are being massacred,” said local resident Louis Ngakossi speaking from the capital Bangui.

The country has seen more than a year of unrest since the Seleka seized power in a coup in March 2013, installing their leader as president until he resigned last January, giving way to a transitional regime.

Armed ex-Seleka rebels from the Muslim community and Christian militias have been accused of causing thousands of deaths, and the violence has led to as many as a quarter of the population being displaced.