Mainly Christian anti-Balaka rebels killed at least 25 Muslims inside a mosque in the town of Kembe in south-central Central African Republic.

The rebels surrounded and attacked the Djimbi Mosque in the early hours of Wednesday morning, Abdouraman Bornou, president of the council of elders of Kembe, said on Friday.

During the attack, the imam and his deputy were executed, Bornou said.

Ousman Mahamat, a Muslim community leader, said he was outraged at the behavior of some of his countrymen who promote inter-communal hatred.

"We have to double our vigilance. We have killed each other. And in this war there is neither a victor nor vanquished," he said.

"What has just happened in Djimbi is devastating,'' he said.

Local authorities ordered three days of mourning in the town.

The diamond-rich but poverty-stricken nation has been in crisis since late 2012, when violence broke out between Muslim and Christian rebel groups.

After a period of relative calm in 2016, fighting erupted again in early 2017 in various towns across the country.

Since 2013 thousands of people have been killed in sectarian conflict in the country, and thousands have fled their homes to seek refuge in neighboring countries, including Cameroon and Chad.

In a report, Amnesty International has estimated that more than 5,000 people, most of them civilians, have died in sectarian violence in the Central African Republic despite the presence of international forces.

Violence erupted in the central African state in 2013, when Muslim Seleka rebels ousted then-President Francois Bozize, a Christian leader, who had come to power in a 2003 coup.

Fierce fighting has continued between Muslim Seleka and Christian anti-Balaka rebels.