A shoot-out between rival vigilantes in Mexico's western Michoacan state has left 11 dead, authorities have said.
The incident, which occurred on Tuesday, signaled a renewed unrest in an area President Enrique Pena Nieto's government said had been pacified.
The federal government's security commissioner for the state, Alfredo Castillo, said that the clash pitted two rival vigilante groups against each another in the town of La Ruana, about 241km from Morelia, the state capital.
On Sunday, vigilante groups blocked several highways in Michoacan, but there were no reports of injuries or major damage.
At the start of 2014, Pena Nieto ordered reinforcements to Michoacan to wrest control of the state from a powerful drug gang, and later forged an uneasy alliance with vigilante groups to restore order.
The unrest in Michoacan follows rising anger about a lack of security in Mexico, where the abduction and presumed killing of 43 trainee teachers has sparked mass protests across the country.
The vigilante groups emerged more than a year ago when farmers and ranchers organised and armed themselves to confront drug traffickers in the violent state.
In May, some members of "self-defence" groups were demobilised and integrated into a government-sanctioned rural police force.