State radio in Cameroon says prison guards have killed 16 inmates trying to escape from a jail in the country’s commercial capital.

State radio says three other prisoners were wounded in the failed escape attempt Sunday in Douala.

A guard told The Associated Press that the inmates managed to cut the prison’s main electricity lines and at least two were armed with pistols. He declined to be identified because he is not authorized to speak to the media.

The overcrowded prison was built in the 1930s to hold about 800 inmates _ but has at least twice that number.