Mexico prison riot: Apodaca boss and guards arrested Published duration 22 February 2012

image caption The prison guards will be held in custody while investigations continue

The director of a Mexican prison and 28 guards have been arrested on suspicion of helping a mass breakout and massacre by gang members on Sunday.

Thirty inmates with links to the Zetas drugs cartel escaped from the Apodaca jail during the unrest and 44 prisoners from a rival gang were killed.

Investigators say they have evidence that guards helped plan the killings.

There were further disturbances in the jail on Tuesday as three Zetas gang members were moved to another prison.

The bloodshed in the jail outside the northern city of Monterrey was one of the worst episodes of prison violence Mexico has seen in recent years.

Prison guards plotted with the Zetas gang to organise the mass escape and slaughter members of the rival Gulf Cartel, the authorities said.

The 44 dead prisoners were stabbed, strangled or beaten to death.

'Direct attack'

"The investigation has discovered direct participation in the riot and that others helped in the escape," Nuevo Leon state prosecutor Adrian de la Garza said.

"We can deduce that this was not just a gang fight, but rather homicides committed in a direct attack on certain persons who were detained there," he added.

Among those detained are the prison director, Geronimo Martinez, his deputy, Juan Hernandez, and the security chief Oscar Laureno.

The 29 suspects are being held in custody while investigations continue.

Gang violence and corruption are common in Mexico's prison system.

But the scale of the violence in Apodaca and the allegations of complicity have caused widespread shock and anger.

Mexico's Human Rights Commission has started its own investigation into the incident and has urged the authorities to do more to prevent violence in prison.

On Monday Nuevo Leon governor Rodrigo Medina said prisons in the state had been struggling to cope with an influx of violent criminals arrested during the military-led campaign against drug cartels.