According to Ecuador's authorities gang rivalry at three jails in the country's overcrowded prison system resulted in at least 75 dead among inmates and several more injured.

As security forces battled to regain control, family members waited for news outside the prison in Ecuador's western port city of Guayaquil, where officials said 21 died.

According to the autorithies another 33 prisoners died at the prison in Cuenca in the south and eight in Latacunga in the centre of the South American country.

Ecuador's President Lenin Moreno, on Twitter, attributed the riots to "criminal organisations" engaged in "simultaneous acts of violence in several prisons". The authorities, he said, "are acting to retake control".

The military was deployed to help police quell the uprising.

The public defender's office called the violence "an unprecedented massacre" and expressed its "concern over the lack of security in the country, which is reflected in the increase in crime and violence inside these prison facilities."

The prosecuting authority said several inmates were left injured in fighting between "criminal gangs", including two at Guayaquil in serious condition.