The African Union on Monday condemned "massacres" in the east of the Democratic Republic of Congo that killed 150 people in June.

African Union Commission chief Moussa Faki Mahamat said he had learned with "dismay of the increasing massacres of innocent civilians" by the Allied Democratic Forces (ADF), in Beni and Lubero in North Kivu province.

"The Chairman of the Commission strongly condemns these attacks, which have claimed the lives of 150 people since the beginning of June," the statement said.

Mahamat encouraged "Congolese authorities, in collaboration with the countries of the region, to intensify their efforts to curb the spread of the terrorist threat in the Great Lakes region".

He also reiterated the African Union's "ongoing commitment to the countries of the Great Lakes region in their fight against terrorism".

The attacks are attributed to the ADF, which originated in neighbouring Uganda.

The group has operated in eastern DR Congo for decades and in 2019 it pledged allegiance to the Islamic State group, which portrays the ADF as its central African branch.

Since the end of 2021, the Congolese and Ugandan armies have conducted joint operations against the ADF in North Kivu and neighbouring Ituri province, but have so far failed to stop the deadly attacks on civilians.

The east of the country has been plagued by violence from armed groups for decades.