BUJUMBURA, Burundi (AP) — Four people were killed Tuesday night in the Burundian capital of Bujumbura as violence persisted following the controversial re-election of President Pierre Nkurunziza.

The four friends were shot in a bar, an apparent revenge attack against members of the ruling party, said witnesses in the volatile neighborhood of Musaga.

Musaga resident Pascal Nsengiyumva said it was "horrible to wake up with people killed beside us." The bodies were still at the crime scene Wednesday morning as residents waited for the police to arrive.

Earlier this month, a former head of the intelligence services and a key ally of the president, Lt. Gen. Adolphe Nshimirimana, was killed in a drive-by shooting in Bujumbura, sparking concerns of revenge killings as regime loyalists and opponents target each other. Nshimirimana is believed to have helped the government defeat an attempted military coup in May.

The day after Nshimirimana was killed, there was an assassination attempt on Pierre Claver Mbonimpa, a prominent rights activist and government critic.

On Saturday, a former army chief of staff during Burundi's civil war, Col. Jean Bikomagu, was shot and killed outside his home in Bujumbura.