Law enforcement officials say a group of armed men stormed a party in this violent northern border city, killing 13 teens and young adults and injuring about two dozen.

The bodies of the victims, whose ages ranged from 15 to 20, lay scattered around the house where the attack happened Saturday night. Ambulances and federal police carried the wounded to nearby hospitals. Their conditions were not known Sunday.

Police officials, who asked that their names not be used because they had not been authorized to discuss the slayings, said witnesses told them there were at least 15 attackers.

Violence also rocked the oceanside Mexican community of Lazaro Cardenas overnight. Police in the southwestern city say that just after midnight Saturday, about 20 heavily armed gunmen riding in trucks with tinted windows attacked a police station with grenades and assault rifles, killing a police officer and two civilians — a mother and her son who had come to pay a fine.

Also early Sunday morning, three women and two men, all identified as Mexican citizens, were murdered while driving in their van with California license plates near the western Mexican city of Navolato.

The bodies of the five victims, including a 16-year-old girl, were found riddled with bullets, said Martin Gastelum, attorney general for the state of Sinaloa, where Navolato is located. Authorities also found more than 60 spent shell casings from Kalashnikov assault rifles in the van, Gastelum said.