MEXICO CITY (AP) — A brutal fight between two rival groups of inmates at a prison on Mexico’s Gulf coast Tuesday left six prisoners dead and nine wounded.

Police in the state of Tabasco said the riot occurred in the patio of a prison in the state capital, Villahermosa.

Police said the inmates used home-made weapons, which in Mexico usually consist of crude blades fashioned from bits of metal, spoons or hacksaw blades.

Authorities said they had regained control of the facility, but did not provide further information on the condition of the wounded.

Drug gangs, including remnants of the old Zetas cartel, operate in Tabasco and their members often fight rivals in prison.