CARACAS — Twenty-five people were killed in a prison riot as two groups of inmates waged a gunbattle inside a penitentiary, Venezuelan officials said Monday.

The violence erupted on Sunday at Yare I prison south of Caracas, and one of those slain was a relative of an inmate, said Iris Varela, the government’s prisons minister.

It was the latest in a series of bloody clashes that have erupted inside Venezuela’s overcrowded prisons and become a major problem for President Hugo Chavez’s government.

Varela told state television that 17 of the 25 dead had been identified. She said some of them had been shot multiple times in the head. Forty-three other people were wounded, including 29 inmates and 14 visiting relatives, Varela said.

About 900 women who were at the prison to see inmates when the fighting broke out were still inside, she said. It wasn’t immediately clear why they weren’t coming out.

She said the situation at the prison was stabilized by Monday morning.

Varela said those behind the killings ‘‘are going to have to answer for this.’’ She didn’t provide details about how the inmate’s relative died.

Carlos Nieto, an activist who monitors human rights in Venezuelan prisons, said an inmate’s relative who was inside the prison told him the shootout began during family visiting hours.

Nieto said the gunbattle lasted about four hours and involved groups fighting for control. Nieto said the riot shows that the ‘‘most serious prison problem, the weapons possessed by inmates, hasn’t been solved.’’