The Mexican government has freed six activists who fought to protect their community's water supply, acknowledging that their rights were "seriously violated" during more than a dozen years in jail.

The six activists from the town of Tlanixco had been sentenced to up to 50 years for the death of a Spanish flower grower. Tlanixco residents had claimed their drinking water supplies were being soaked up by commercial flower growers in a neighboring town.

Government authorities declined to continue fighting appeals by the six activists.

The government's top human rights official says President Andrés Manuel Lopez Obrador's administration is currently reviewing 538 cases involving people who may have been unfairly jailed. Alejandro Encinas said Thursday the pending cases often involve people fighting to defend water and land rights.