Seven inmates died and 37 other people, including eight relatives of prisoners, were wounded in a fight at the jail in Cabimas, a city in Venezuela's Zulia state, media reports said Thursday.

"The violent incidents were the product of internal frictions due to overcrowding. There should be 120 inmates here, but we house nearly 600. There are inmates who have been here since 2007 and remain without trial for crimes," Zulia Government Secretary Julio Lopez said.

Four of the wounded inmates are listed in serious condition at Cabimas Hospital, Lopez said.

The fight started on Wednesday afternoon during visiting hours, the official said.

About 100 National Guard personnel and Zulia state police took control of the prison, where they seized a pistol and bullet casings for several weapons that have not been found, as well as knives and razors.

The cell block where the fight occurred is 300 percent overcrowded, Zulia Deputy Security Secretary Wilfredo Borraz said.