Relatives of inmates wait for information of their loved-ones after a prison riot at La Pila prison in San Luis Potosi, April 27, 2013. [Photo/Agencies]

MEXICO CITY - Thirteen inmates were killed and 65 others injured in a prison riot Saturday in the central Mexican state of San Luis Potosi, local authorities said.

A clash erupted when a group of inmates, fed up with harassment by other prisoners, attacked their rivals before daybreak at the La Pila prison in the state capital, according to the state attorney general's office.

At least 100 inmates were involved in the deadly riot.

State Governor Fernando Toranzo said at a press conference that 13 inmates had died and 22 of the 65 injured were in serious condition.

Violent disputes between rival cartels and drug gangs have often spilled over to Mexico's overcrowded prisons.