5 February 2011 Last updated at 20:12 ET

Mexican prison official murdered in Monterrey

The security chief of a prison in the northern Mexican city of Monterrey has been murdered, officials say.

Police found the dismembered body of Francisco Martinez Ramirez in a plastic box inside a car abandoned near the Topo Chico prison.

Mr Martinez Ramirez, 60, who had worked there for three decades and was nearing retirement, had been abducted on Friday.

He is the third employee to be murdered at the jail in recent months.

The Topo Chico prison has also been the target of a series of grenade attacks.

Drug cartels wield considerable influence over Mexico's prisons, through their ability to bribe and threaten guards.

Criminal message

Mr Martinez Ramirez's family said armed men broke into his home on Friday afternoon and kidnapped him.

In the early hours of Saturday, locals reported an abandoned vehicle in the car park of a pharmacy near the prison.

On the back seat, police found a plastic box with Mr Martinez Ramirez's mutilated remains.

Police say a message from a criminal gang was pinned to the box, but did not say what the message was.