COATZACOALCOS, Mexico - A municipal mayor in Mexico 's violent eastern state of Veracruz was killed Friday, local authorities said, just four days after a mayor-elect was murdered in the same state.

Victor Manuel Espinoza - mayor of Ixhuatlan de Madero, located some 270 kilometers (168 miles) northeast of Mexico City - "was killed with four others including his wife" in the attack, the state prosecutor's office said in a statement. Authorities did not provide details concerning a possible motive for the attack, which occurred Friday night on a dirt road in a neighboring municipality near the state's capital Xalapa.

The murders came days after a group of at least 30 armed men murdered Santana Cruz Bahena, mayor-elect of the municipality of Hidalgotitlan. That act was allegedly linked to a criminal gang that traffics stolen fuel.

Three more mayors were assassinated in other Mexican states last month, while nearly 50 have been killed since 2003, according to figures from the National Association of Mayors.

Violence in Veracruz has risen in 2017 compared to the year prior, with 1,382 murders documented from January to October - a figure that already exceeds 2016's total 1,258 homicides.

The state government ascribes the rise in violence to power struggles between crime gangs involved in drug smuggling, illegal immigration from Central America and the theft of fuel from pipelines.

Around 190,000 people have been killed in Mexico since 2006, when the government launched a military campaign on the drugs cartels. The numbers do not show how many of the victims were linked to crime groups.