Thirteen inmates at a prison in Venezuela have died after ingesting drugs obtained during a riot, the Ministry for Public Power of Penitentiary Services said Thursday. "Around 8:30 a.m. [Monday] they became violent and started to break the walls and the doors of the confined areas, so the National Guard was called in for support," the statement said.

The inmates, all of whom were on a hunger strike, gained access to the pharmacy and began taking a range of drugs. While 13 died, a further 130 were treated by medical staff at the prison after ingesting drugs such as antibiotics, antihypertensive drugs, anti-diabetic agents, anti-epileptic drugs, and alcohol, although there has been no independent verifiction of what took place. 

"I doubt the official version," said Marianela Sanchez, legal coordinator with the nongovernmental organization Prison Observatory. 

"I don't think an inmate grabbed a flask and drank it, that's stupid," she said, calling for an investigation. "Something happened and the results are catastrophic."

The hunger strike began at the David Viloria prison in Lara State Monday with prisoners demanding the dismissal of a disliked officer, who they believed had been appointed the new director of the prison.

Relatives of the inmates camped out Tuesday as they waited to quiz Minister of Penitentiary Services Iris Varela.

Access to the prison for media and family has been difficult since National Guard troops were called to guard the prison until the situation can be resolved, according to Globovision.

In all, 720 prisoners have been moved to other prisons, but as yet, families members have not been told where, Globovision reported.

The deaths are a setback to the country’s ongoing prison building program, aimed at improving the overall conditions. The prison system has been plagued by violence and poor conditions for decades.