SAO PAULO — Gunmen attacked a prison in northern Brazil trying to stage a mass escape of inmates Tuesday, setting off a gunbattle with police that killed 20 people and injured at least four, authorities said.
Public security officials in Para state identified 19 of the dead as prisoners or their supporters. A guard at the Santa Izabel penitentiary in the metro area of the state capital of Belem also died.
Officials were doing a head count inside the prison to determine whether any inmates escaped.
In a statement, police investigator Rodrigo Leao said two assault weapons, three pistols and two other guns were seized from a group that tried to break into the prison to facilitate a breakout by inmates.
The attempted breakout began when explosives were used against a prison wall, according to a statement from the state's public security secretariat. Police and guards then exchanged gunfire with the armed men trying to help inmates escape and with inmates themselves who were armed, it said.
It wasn't immediately clear how many of the dead were inmates and how many were gunmen trying to help them escape.
Latin America's largest nation has more than 726,000 prisoners, one of the largest inmate populations in the world. Many of its prisons have terrible conditions, and gang leaders often run drug businesses from behind bars.
Last year, gang wars in prisons led to massacres that resulted in at least 125 deaths.