Blasts from two fragmentation grenades injured a Mexican tourist and a police officer in the Pacific resort of Zihuatanejo, packed with Holy Week visitors, officials said Thursday.

The grenades were tossed late Wednesday night at the municipal police station and at an office of federal anti-drug police. The blasts occurred about 10 minutes apart, said Mayor Silvano Blanco.

An 18-year-old tourist from the neighboring state of Michoacan suffered minor injuries, but a 44-year-old police officer was listed in serious condition, Blanco said.

The state of Guerrero, which includes Zihuatanejo and Acapulco, has suffered from a wave of violence including decapitations, shootings and grenade explosions that authorities attribute to warring drug-trafficking gangs.