Shooters killed nine people, including a 12-year-old boy and four teens, in a blaze of gunfire at a slot-machine arcade in the central Mexican state of Michoacan, part of a wave of violence sweeping the country's avocado heartland.
Michoacan's attorney general said in a statement late on Monday that eight people died during the arcade shootout in Uruapan, the state's second-largest city. Another person died while receiving medical attention and others were injured.
The youngest victims were aged 12 and 13. Others aged 14, 17 and 18 also died, the prosecutor's office said. Footage on social media showed bodies lying in pools of blood on the floor of the arcade.
Authorities did not give a motive for the attack in Uruapan, a city that has long suffered from high violence as gangs vie to control production and transport of drugs such as crystal meth, and increasingly the lucrative avocado trade.
While it is rare for children to be targeted, drug gang feuds were largely responsible for Mexico's worst recorded year of violence last year, with a record of more than 34,600 victims. Drug gangs in Mexico are also often involved in extorting money from slot machine businesses.
Increasingly, critics have blasted government security measures and low conviction rates.
Mexican media reported the shootout was linked to a dispute between rival cartels seeking to control the trade in synthetic drugs. A spokeswoman for the attorney general declined to comment, adding that the investigations are ongoing.
Uruapan is a major center for the processing and export of avocados grown in orchards that spread across Michoacan's hillsides.
The prosecutor said four shooters had used weapons only authorized for the Mexican military. In the aftermath of the shooting, it said authorities had found 65 9 mm shell casings in the arcade. Over the weekend, state authorities also reported the discovery of a mass grave of 11 partially decomposed bodies in the Uruapan area as local authorities were searching for a disappeared person.
Last week, the arrest of a senior leader of the Los Viagras gang in the Uruapan area led gang members to burn vehicles and blockade roads.