Nairobi/Yaounde - Prison guards in Cameroon have shot dead at least 16 convicts during a prison-break attempt, reports said Monday.

Inmates at a prison in the port city of Douala first cut the power and then temporarily overpowered guards before being fired upon, British Broadcasting said, in a report monitored in Nairobi.

Another three prisoners were injured and taken to hospital.

Many of Cameroon's prisons are overcrowded and outdated, leading to frequent attempts to escape. (dpa)