At least 15 people have been bludgeoned to death with stones and cement blocks, and some bodies partly burned, in an indigenous village in southern Mexico plagued by a dispute over windpower.

The municipal government of the Pacific coast community of San Mateo del Mar in Oaxaca state said 13 men and two women were killed at the weekend by what it described as a group of six people with the support of a local crime boss. Activists who successfully opposed windpower projects say the mayor’s followers ambushed them at a coronavirus checkpoint.

The prosecutor’s office in the southern state confirmed the figure of 15 dead, and said a detachment of four detectives, 80 state police and 39 national guard members had been sent to the scene of the killings, the village of Huazantlán del Río. Investigations were under way into the reasons behind the killings and if the attackers had guns.