A mass shooting in Guadalajara’s metropolitan area Saturday left 11 people dead and two seriously injured, closing out a violent month.

According to the Jalisco Attorney General’s Office, armed men in multiple vehicles arrived around 6 p.m. Saturday at an intersection in the city of Tonalá and began shooting at a group of men sitting on the sidewalk.

The site is known as a place where local laborers congregate after work and wait to be paid their weekly salaries, neighbors said.

The armed group shot over 70 times at the male construction workers who had just gotten off work, authorities said.

Among the people killed was a man in charge of paying the workers, as well as his son, according to the newspaper El Universal. A witness told the newspaper Informador that the boy was about 12 years old.

Another man died inside a nearby home.

The two people who were injured were bystanders: a 35-year-old woman and her 5-year-old son, both of whom were shot by stray bullets. They remain hospitalized.

The assailants fled immediately after the shooting. Police said they have no leads, despite local, state and federal authorities spending several hours on Saturday night searching for the suspects and doing helicopter flyovers.

It was the fourth multiple homicide reported in the city’s metropolitan area during February, and the one with the highest death toll. The most recent incident occurred on February 18 in San Pedro Tlaquepaque, when an armed gang killed five people on a farm during daylight hours in the Guayabitos neighborhood.

Another attack on February 17, which took place around dawn in a public park in Guadalajara, left four dead, while on February 10, an armed group shot and killed five people in Tlaquepaque.

Sources: El Universal (sp), Informador (sp), Milenio (sp)