Seven women and three men were killed at the scene in shootings in two bars, according to a statement by security officials in Celaya, Guanajuato state, which said the attack happened in the Valle Hermoso neighbourhood. An eleventh victim, a woman, later died at the hospital, according to a state government spokesperson. Two other people were wounded.

Pieces of cardboard with messages “alluding to a criminal group” where found at the scene, the statement said.

Some 15 gunmen took part in the attack, Mexican newspaper El Universal said. The assailants also threw molotov cocktails in the attack, according to a paper.

Mexico’s National Guard, the Defense Ministry and Guanajuato state security forces were searching for the gunmen, security officials said.

Guanajuato has become one of the most violent regions of Mexico in recent years, as drug gangs battle for control.

Government data show there were 993 homicides in the first four months of 2022 in Guanajuato, giving it the second-highest total behind the western state of Michoacan.