Prison riot kills 52 in Mexico

At least 52 men died in a northern Mexican prison on Thursday as inmates ignited a fire during a brawl between two rival groups, authorities said.

Governor Jaime Rodriguez said the clash erupted at the Topo Chico prison in the industrial city of Monterrey before midnight on Wednesday and that authorities brought it under control at 1:30 am on Thursday.

"We are experiencing a tragedy stemming from the difficult situation that they are living through at penitentiary facilities," Rodriguez told a news conference.

"We can confirm the deaths of 52 people. ... The process of identifying victims continues," he said, without specifying whether prison guards were among the dead.

He said all the victims were men, rejecting fears that women or children may have been inside at the time of the riot.

Twelve inmates were injured, five of them in serious condition.

The fight involved a group led by a leader of the Zetas drug cartel, he said. During the brawl, inmates set fires in supply rooms.

Troops and federal police were deployed inside the prison to keep it under control. Rodriguez said no inmates escaped from the prison.

The riot erupted on the eve of Pope Francis' trip to Mexico, during which he is due to visit another notorious prison, in the northern border city of Ciudad Juarez.

Mexican penitentiaries are notoriously overcrowded and massive prison breaks have taken place in recent years.