Rebels linked to the Islamic State (IS) group have killed more than 50 people at a funeral ceremony in eastern Democratic Republic of Congo, officials have said.

Most of the victims were hacked with machetes in the night-time assault by the Allied Democratic Forces (ADF) on a village in North Kivu province, officials added.

This is the latest in a string of attacks linked to the ADF, raising fears that its insurgency is growing in strength.

The ADF emerged in Uganda in the 1990s, accusing the government there of persecuting Muslims. It is now based across the border in DR Congo and carries out attacks in both countries.

"I can confirm a provisional death toll of 50. The victims were caught off guard at a mourning ceremony in the village of Ntoyo," Macaire Sivikunula, a local administrator, was quoted as saying by Reuters news agency.