At least 16 people were killed by a suspected Islamist rebel group based in eastern Democratic Republic of Congo's North Kivu province, an official from the local administration said on Wednesday.

The Allied Democratic Forces (ADF), allied to Islamic State, started as a Ugandan insurgency but has operated from the jungles of eastern Congo for almost three decades.

"We believe that the ADF are the perpetrators of this attack, they took advantage of the departure of the military in the area to come and kill the population," local official Fabien Kakule Viriro told Reuters.

The victims were hacked to death with machetes while they were in their homes or in the fields, the official said, adding that some were executed while they were trying to escape.