A shootout between rival drug trafficking gangs left at least 28 people dead on a highway near the town of Ruiz in Nayarit, west Mexico.
Later reports moved the death toll up to 30.
The Mexican Navy took control of the area, while stores closed, leaving the town deserted.
The authorities discovered at least ten abandoned vehicles and various weapons, as well as four wounded people. From footage of the scene, many seem to have been dressed in full combat gear. (See XHKG's video report below).
Drug violence has shot up in the last year in the Pacific state of Nayarit, which is a center for heroin production. Control of the region has been in flux since the July 2010 death of Sinaloa Cartel head Ignacio "Nacho" Coronel Villarreal.
Meanwhile, Mexican authorities attributed the killings to a dispute between the Sinaloa Cartel and the Zetas, and said that the Beltran Leyva Organization could also be involved.