Officials said nine people were killed and another wounded when gunmen opened fire following the shooting in the central Mexican state of Guanajuato.
Public Security officials in Celaya said in a statement that the militants arrived late at night. Local newspapers reported that a memorial service for a man was killed the day before. Pictures from the scene showed bodies strewn across the street.
Guanajuato is at the center of a bloody guerrilla war between rival organized crime groups. There were no immediate reports of who was responsible for the killing. Thousands have been killed in Guanajuato since the local Santa Rosa de Lima gang confronted the Jalisco New Generation Cartel in 2017.
Authorities arrested the leader of the Santa Rosa de Lima cartel in August, but the violence continued.
The Santa Rosa gang grew up in a farming village of the same name by stealing fuel from government pipelines and refineries and stealing goods from trains. But after the authorities stepped up security measures around trains and pipelines over the past two years, the gang turned into extortion and kidnapping.
The Jalisco New Generation Cartel has been the most violent in Mexico in recent years, aggressively expanding its reach across the country through audacious attacks against rivals and government forces.
Their conflict has made Guanajuato – the home of charming San Miguel Allende, a popular retirement home for Americans – the bloodiest state in Mexico.
In September, gunmen killed 11 people at a bar in Jarral del Progreso, near the border with Michoacan state. More than twenty people were killed in an unregistered drug addiction rehabilitation center in Irapuato in July.