Tegucigalpa, Honduras ? A shootout between inmates at Honduras’ biggest prison left at least 13 inmates dead and another 30 wounded Thursday, officials said.

The confrontation began at the National Penitentiary on the outskirts of Tegucigalpa, the capital. Honduran Security Minister Armando Calidonio said police and guards had restored control at the facility, and that at least one of the wounded inmates suffered serious injuries.

“The confrontation was between two rival groups of prisoners who fired shots at each other in a territorial dispute,” Calidonio said.

He said officials had yet to determine how inmates got guns into the National Penitentiary, but said police are “intensively investigating” the clash.

Police and army troops have mounted security around the prison, Calidonio said.

The clash occurred at a cellblock known as the “Casa Blanca,” which holds about 200 of the prison’s most dangerous inmates.

Those involved appeared to be nongang inmates, and members of the feared “Mara” street gangs who have been involved in past incidents apparently played no part in Thursday’s clash.

At least 27 inmates were murdered in 2005 at the prison, most by their cellmates. Nearly 600 prisoners rioted at the facility in 2004 to protest the transfer of four of their leaders to another facility. No injuries were reported in that incident.

Honduras’ overcrowded, aging prisons frequently have been the scene of riots and fights between the country’s 13,000 prisoners.

Only about 30 percent of inmates in Honduran prisons have been convicted; most wait anywhere from five to eight years for their cases to be decided.