Cuba invited foreign journalists to tour four prisons this week in an apparent attempt to counter public criticisms of conditions inside.

At the Combinado del Este, the island's largest lockup and one of five maximum-security prisons, reporters were shown workshops where inmates were hard at work disassembling cars, repairing motors and making shoes.

The prison, which is home to Cuba's gravest offenders, also offers classes in useful skills like bricklaying, carpentry and soldering.

Roelis Osorio, director of the Combinado del Este, said 27 percent of the inmates work voluntarily and are compensated for their labor. He said 37 percent of prisoners take classes.

Cells measuring about 2 by 4 yards (meters) house three inmates, and each has a bathroom separated by plastic curtains or blankets.

Medium-security prisons were also opened up to reporters for the first time in nine years.

Cuba has 56,000 prisoners in 200 penitentiaries.

Cuban dissidents have accused prison facilities of abuse amounting to torture — something vehemently denied by authorities.