Rioting inmates at a Mexican prison slit their rivals' throats and beat them to death Thursday, leaving 28 dead in the latest explosion of violence in the country's often lawless jails.

Bodies were found strewn around the maximum-security wing, the kitchen, a prison yard and a conjugal visits area after the pre-dawn riot at the Las Cruces federal prison in Acapulco, said the security spokesman for the state of Guerrero.

"The incident was triggered by an ongoing feud between rival groups within the prison," the spokesman, Roberto Alvarez, told a press conference.

It was the latest deadly riot in Mexico's chronically overcrowded prisons, where corruption abounds, inmates often have de facto control, and contraband weapons and drugs are rife.

The Guerrero governor has ordered an investigation of all prison staff, Alvarez said. State police have temporarily taken control of the prison, backed by federal police and the army, which set up a security cordon outside.

Officials initially gave a death toll of five and indicated the riot was limited to the maximum-security wing. But the toll soared as police searched the rest of the prison.

Three more inmates were wounded in the violence, Alvarez said.