PUERTO VALLARTA, Mexico (AP) Mexican authorities say at least 16 people have been injured by a grenade that exploded at a bar in the resort city of Puerto Vallarta.

Jalisco state prosecutors say five of the injured have been detained as part of the investigation. Four of those detained each lost a leg in the explosion before dawn Thursday.

Prosecutors say they are investigating whether one of the injured was carrying the grenade when it exploded.

Jalisco state has seen a wave of drug violence in recent months and the bloodshed has intesified since drug kingpin Ignacio ``Nacho'' Coronel was killed by soldiers earlier this month. Coronel, whose base was in Jalisco, was the No. 3 of the Sinaloa drug cartel.