BANGUI (Reuters) - At least 15 people including a priest were killed and scores wounded in Central African Republic’s capital Bangui on Tuesday when unidentified gunmen attacked a church, a morgue official and rights groups said.

The attack occurred on the border of the predominantly Muslim PK 5 neighborhood where 21 people were killed last month when a joint mission by U.N. peacekeepers and local security forces to disarm criminal gangs descended into open fighting.

Witnesses said Notre Dame de Fatima church was attacked with gunfire and grenades during a morning service, forcing trapped churchgoers to escape through a hole made in the church wall by police.

“Filled with panic, some Christians began to flee until bullets and grenades began to fall in the parish grounds, trapping those who remained in the compound,” Moses Aliou, a priest at the church, told Reuters.

Nine dead bodies were taken to Bangui’s Community Hospital, a morgue official said, while aid agency Doctors Without Borders said six people had died and 60 were wounded at other hospitals where it operates.

It is not clear if they were all killed in the church attack itself or during skirmishes that occurred afterwards in the surrounding area.

A priest named Albert Toungoumale Baba was among those shot dead during the attack, said the Chancellor of the Archdiocese of Bangui, Walter Brad Mazangue.

A crowd of thousands of angry, shouting protesters gathered as his body, covered by a sheet, was carried on a makeshift stretcher along dirt streets to the presidential palace, a Reuters witness said.

Although the gunmen were not identified, Central African Republic has seen frequent incidences of inter-faith violence since 2013 when mainly Muslim Seleka rebels ousted President Francois Bozize.

Retaliation killings followed by “anti-balaka” armed groups, drawn largely from Christian communities, and Muslim “self-defence” groups sprang up in PK5, claiming to protect the Muslim civilians concentrated there against efforts to drive them out.

The same church was previously attacked in 2014, when gunmen with grenades killed a priest and some worshippers.

After last month’s deaths in PK5, demonstrators who blamed U.N. soldiers for firing on residents protesting against the operation to counter armed groups carried the bodies of the dead to the gates of the U.N. mission, known as MINUSCA.

MINUSCA and the police were not immediately available for comment on Tuesday.