More than 20 people were killed in a clash between inmate gangs at Yare I prison in suburban Caracas, Venezuela's minister of penal services said Monday.

"Yes, (the deaths) surpass 20," Iris Varela told state television, noting that one of those killed in Sunday's confrontation between two "heavily armed" groups was an inmate's relative who was at the prison for visiting day.

"Today it's calm, as if nothing had happened," the minister said.

The situation of Venezuela's prison system is "truly difficult," she said.

"We all know the prisons are a time bomb. If there are problems in the street, how can there not be in a penitentiary?," Varela said.

The central government accepts "the responsibility that belongs to it", she said, while rejecting what she saw as opposition attempts to exploit the incident at Yare I for political gain less than two months from Venezuela's presidential election.

Violence and escapes also happen at prisons in opposition-ruled states, the minister said.

"There are no moral conditions for these people to go on the attack over a problem that we recognize is present, that we are making all the efforts in the world - and the Venezuelan people know it - to counteract that problem, which is a structural problem," Varela said.

The Venezuelan government says the serious problem with weapons inside the country's vastly overcrowded prisons will be addressed as part of a restructuring of the penal system.

Violence in the Andean nation's prisons claimed 304 lives in the first half of the year, an increase of 15 percent over the same period in 2011, the independent Venezuelan Prisons Observatory said Monday.

Two days later, the Prisons Ministry reported that guards confiscated 22 firearms - including a submachine gun - and two tear-gas grenades from inmates at a penitentiary in the central state of Carabobo.

Also seized were more than 2,000 bullets, three knives, three computers, 98 cell phones and 98 packets of illegal drugs, ministry official Mary Pili Viera said.

The ministry was created a year ago after a month-long standoff between army troops and nearly 1,000 armed inmates at another prison on the outskirts of Caracas. EFE