At least 11 people were killed and 30 arrested during clashes between civilians, militiamen and police on Sunday in southern Mexico.

At least 18 people died in armed clashes over the weekend in Acapulco and Los Cabos, two seaside resorts on the Pacific coast of Mexico, adding to a new wave of violence in the country’s tourist centers.

In Acapulco (Guerrero province), a group of militiamen opposed to a dam construction project attacked the inhabitants of the village of La Concepcion, who gathered for a party, on Sunday morning.

The armed attack left eight dead, according to a security official for the province, Roberto Alvarez Heredia. The militia then struck a second time, this time targeting members of the army and police deployed in the commune, but were repulsed by the police, who shot dead three militiamen according to Mr. Heredia .

The operation resulted in the arrest of 30 of these “community guards”, along with their leader, Marco Antonio Suastegui Munoz, and the seizure of 580 doses of cannabis and seven weapons, said State Attorney Xavier Olea.

On Saturday night, a clash between hired gunmen and Mexican Navy soldiers killed seven people in San José del Cabo (Baja California), according to local prosecutors.

The first elements of the investigation indicate that the soldiers patrolled when they notified two vans in which were seven men armed with assault rifles, indicates the floor in a statement. A chase and shootings on a highway leading to the town of Cabo San Lucas followed.

The authorities seized seven weapons, ammunition and two vehicles registered in California, one of them declared stolen in the border town of Tijuana.

The region of Baja California Sur, a seaside area frequented by American, Canadian and European tourists, has been experiencing a growing wave of organized crime violence for several months.

On Tuesday, a family of five was the target of a raid by an armed group, which killed both parents and injured the three children.

According to official figures, 499 people were murdered in Baja California Sur between January and November 2017, a figure that has doubled since the previous year.

Cartels operating in Mexico, such as Sinaloa or Nueva Generaction, are fiercely fighting over control of territories for cultivation and drug trafficking, such as cannabis and opium, as well as tourist areas for sale.