Gunshots were reported at the bar in the city of Irapuato in the central state of Guanajuato at close to 8 p.m. local time Saturday, the city’s Secretary of Citizen Safety said in a statement as quoted by CNN.

Paramedics confirmed the deaths of six men and six women after arriving on scene, according to the statement.

The identity of the gunman is still not known.

A search operation for the attackers is underway with support from Guanajuato’s Secretary for Public Safety as well as the state’s prosecutor general’s office, the Secretary of National Defense, and the National Guard, reports CNN.