At least 68 people were killed in a fire at a prison in Venezuela's Carabobo state, according to a government official.

"The Public Prosecutor's Office informs the public that in the face of the terrible events that took place at the General Command of Carabobo, where 68 people died in the wake of a fire, we have appointed four prosecutors to clarify these dramatic events," Chief State Prosecutor Tarek Saab tweeted on Wednesday.

The Scientific, Penal and Criminal Investigation Service Corps (Cicpc) as well as the Prosecutor and the director of the Carabobo Police Jose Aldama, are investigating to identify the cause of the incident, reports Efe news.

The blaze reportedly started after prisoners set fire to mattresses in an attempt to break out on Wednesday.

Relatives surrounded the station after news of the fire broke.

The situation soon turned violent, leading the 20 state police officers who were guarding the station to launch tear gas.

Last month inmates at a different prison in Carabobo took a number of prisoners and guards hostage in another riot.