Gunmen have killed the mayor of the Mexican municipality of San Mateo Piñas in the latest deadly attack on local officials.

Witnesses said four armed men arrived on motorcycles, stormed the village hall and opened fire on the mayor, Lilia Gema García Soto, and a local official who was in a meeting with her, Eli García Ramírez.

Two municipal police officers were also injured in the attack.

While officials are still investigating the possible motive for the killing, local officials are often targeted by criminal gangs for failing to do their bidding.

García Soto is the second mayor to be killed in Oaxaca state this year. In May, the mayor of Santiago Amoltepec was shot dead in an ambush along with two other people who were in the car with him at the time of the attack.

The governor of Oaxaca has condemned this latest killing, adding that the crime would not go unpunished.

However, security forces are still searching for the four gunmen, who escaped after the attack.

The state prosecutor’s office said federal agents had been deployed to the area to help locate them.

Violence against local politicians and those running for office in Mexico has been on the rise in recent years, spiking in the run-up to last year’s general election.

Most of the attacks happened in small towns where organised crime groups are particularly strong, but last month two top aides of the mayor of Mexico City were shot dead in the capital in an escalation of violence which shocked the country.