File Photo: People search the wreckage of Saint Louis Church in Brazzaville, DR Congo.
Heavy gunfire rang out shortly after the bomb went off, with panicked crowds fleeing the town's center.
Mayor Narcisse Muteba Kashale, who is also a police colonel, said at least two of the victims were children. Wounded survivors were taken to the local hospital, he said.
``Investigations are underway to find the perpetrators of this terrorist attack,'' he told The Associated Press.
The town has long been targeted by rebels from the Allied Democratic Forces, or ADF, a group that traces its origins to neighboring Uganda. But an Islamic State group affiliate claimed responsibility for two explosions in Beni in June, deepening fears that religious extremism has taken hold there too.
Those explosions included the first known suicide bombing in eastern Congo, a Ugandan man who blew himself up outside of a bar. The Islamic State group's Central Africa Province later said that the suicide bomber was targeting Christians. The other explosion that day went off inside a Catholic church, wounding two people.
Residents of the town have repeatedly expressed anger over the ongoing insecurity despite an army offensive and the presence of U.N. peacekeepers in Beni. In recent years, the town also has suffered through an Ebola epidemic and has seen several smaller outbreaks of the disease.