The mayor of the capital of Mexico's violence-plagued state of Guerrero was killed on Sunday (October 6), less than a week after he took office, the state's governor confirmed.

Alejandro Arcos was killed just six days after he took office as mayor of the city of Chilpancingo, a city of around 280,000 people in southwestern Mexico.

The official confirmation came after photos circulated on messaging app WhatsApp depicting a severed head on top of a pick-up truck, appearing to be that of Arcos. Reuters could not independently verify the photos' authenticity. Guerrero's state attorney general's office said it was investigating his murder.

Arcos' death comes just three days after the new city government's secretary, Francisco Tapia, was shot to death. - report from Reuters

(Production: Rodolfo Pena Roja, Daniel Lim)