At least four people have been killed and several injured after a riot was sparked over water shortages at a prison in Ivory Coast, officials said.
Violence broke out early on Tuesday at the main prison in the commercial capital Abidjan's Yopougon district.
The country's top prison official told Reuters news agency inmates were frustrated the water supply had been cut off and they were being rationed.
A UN official said a human rights team would be investigating the incident.
Prison administrator Francois Guei told Reuters that security forces shot dead two prisoners in trying to quell the riot.
"There are four confirmed dead and eight were injured. Some prisoners escaped but we don't know how many yet," he said.
"Two were killed by bullets and it seems two were killed with machetes or knives."
A Justice Ministry official was quoted by the Associated Press as saying prison guards also used air and tear gas.
One man who lives close to the prison claimed he saw inmates trying to escape.
"Some managed to escape by climbing over the wall but the security forces circled the prison and fired shots in the air to stop them getting away," he was quoted by Reuters as saying.
Water was being rationed at the prison after supply to the Yopougon district was cut off several days ago due to a fault.