At least 11 people were killed and another dozen injured when gunmen opened fire on locals who had gathered at a football pitch in the city of Salamanca in central Mexico on Sunday.
Witnesses said armed men arrived at the grounds in several vehicles and shot at those gathered there seemingly indiscriminately.
Many families had stayed behind to socialise after a match between local clubs. At least one woman and one child were among those killed.
The motive behind the shooting is not yet clear. Guanajuato, the state in which Salamanca is located, registered the highest number of murders in the whole of Mexico last year.
Neighbours reported hearing at least 100 shots ring out as the gunmen opened fire at the Cabañas pitch in the Loma de Flores neighbourhood.
Local and federal security forces are now investigating the deadly shooting.
It came just a day after several violent incidents in the city, which included the deaths of five men and the abduction of one.
Guanajuato has seen a spike in violence perpetrated by various gangs involved in the theft of oil and fuel, drug trafficking, and extortion.
Gang members frequently conduct attacks on tanker trucks and oil pipelines belonging to state-run Pemex, especially in Salamanca, home to a major refinery.
Analysts attribute much of the violence to the rivalry between the Jalisco New Generation Cartel (CJNG) and the Cartel de Santa Rosa de Lima (CSRL).
Their operations extend beyond Mexico, affecting drug smuggling routes into the United States.
Last year, the US designated the CJNG as a Foreign Terrorist Organisation, while sanctions were placed on the CSRL.
US President Donald Trump has emphasized the need to combat drug-related violence, claiming that cartels are running Mexico and threatening military action against them.
Recently, Mexican President Claudia Sheinbaum handed over 37 high-profile suspects to the US as part of an effort to cooperate in anti-drug initiatives, aiming to prevent unilateral US actions on Mexican territory.
