CARACAS, Venezuela — Venezuelan media reported on Friday that dozens were killed in a bloody prison riot, and the government said it was investigating.

Vice President Nicolas Maduro called the violence tragic early Saturday on television and said the authorities had launched an investigation.

He and other officials did not give a death toll from the riot at Uribana prison in the central city of Barquisimeto.

The newspaper Ultimas Noticias reported on its website that 54 were killed. The television channel Globovision reported about 50 killed. Both cited Ruy Medina, the director of Central Hospital in the city, who also said that dozens were hurt.

Penitentiary Service Minister Iris Varela said earlier on television that the riot broke out when groups of inmates attacked National Guard troops who were attempting to carry out an inspection.

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The government’s last study of the region dates back to 1983.