At least eight inmates of a prison in Mexico's central state of Jalisco have died following a violent clash on Friday.
Officials added that some died from bullet wounds while others were beaten to death.
Eight more prisoners have been hospitalised with minor injuries.
Authorities said a fight broke out as inmates participated in a sports activity.
Jail staff have recovered two firearms and a homemade explosive device, and detained five people for their alleged role in the incident.


Tehran threatens US businesses, Hegseth says next few days 'decisive'
China, Pakistan call for Iran peace talks, normal navigation in Strait of Hormuz
Two injured after fallen drone debris hits houses in Saudi Arabia
Bangladesh considers partial online classes amid energy crisis
Fire at Russian petrochemicals plant kills at least three
Three UN peacekeepers killed in Lebanon as Israeli strikes pummel south
Russian attacks kill two, injure dozens
