Mexican police now say at least one person died in a grenade attack early Wednesday at a restaurant in Guerrero state.
Authorities revised an earlier statement that said there were no fatalities in the pre-dawn blast in the town of Petatlan. At least 30 people were injured, including the driver for the town's mayor.
It was the second violent attack in the region in a week. Monday in Acapulco, five people were wounded when a grenade was thrown in a residential area.
Officials blame drug smuggling and organized crime for a recent surge in violence in northern Mexico.
Some information for this report was provided by AP.