Four people were killed and five others wounded when gunmen opened fire on patrons at a bar in the Mexican Gulf state of Veracruz, police said.
The attack occurred around 12:30 a.m. Saturday at the La Cabaña de San Pancho bar in Acayucan, a city located 538 kilometers (334 miles) southeast of Mexico City.
The gunmen killed prominent attorney Fernando Alfonso Diz Reyes and three companions, police said.
Five people, including Acayucan Mayor-elect Arturo Gomez Mariño, were wounded.
Gomez Mariño is scheduled to be sworn in on New Year's Eve.
State police and marines responded to the shooting and launched a search for the gunmen, but officials said no arrests have been made.
Marines found a clandestine grave containing seven bodies on Dec. 20 in La Cava, a beach in the city of Alvarado, located 456 kilometers (283 miles) southeast of Mexico City.
The mass grave contained the remains of three women and four men who showed signs of torture.
Army troops found another clandestine grave containing a decapitated body last Wednesday in Agua Dulce, a city in Veracruz state. EFE