Armed men have attacked a prison in the eastern Congolese city of Beni, killing at least 11 people and freeing more than 900 prisoners, according to a DR Congo official.

North Kivu provincial governor Julien Paluku said eight prison guards were among the 11 dead in the Sunday afternoon attack. He said about 30 prisoners remained in the jail.

Paluku announced a curfew in Beni and nearby Butembo, saying only the army and police could circulate. Suspects were not immediately known.The Kangbayi prison is the largest in the northern region of the North Kivu province. Most of the inmates were rebels of the Allied Democratic Forces on trial for massacring civilians since 2014. The Ugandan rebel group has destabilized the region since the 1990s.

"For more than two weeks we have appealed to administrative authorities to reinforce the prison's security," said Gilbert Kambale, president of the town's civil society organizations. "This prison holds some of the most dangerous detainees because of their links with local and foreign armed groups."

Congo's police said Saturday that a group of men attacked a police station in Kinshasa, killing at least two.

In May, Christian sect members stormed a prison in Kinshasa, freeing their leader and others. Witnesses say thousands escaped.

Scores of armed groups fight for control in Congo's mineral-rich eastern region.