MEXICO CITY — The announcement went out on Facebook, an open invitation summoning revelers to a birthday party at the Italia Inn in the northern Mexico city of Torreon.
But early Sunday, as musicians serenaded amid food, drink and dancing, gunmen burst into the party, blocked the exits and, saying not a word, opened fire, killing 17 men and women and injuring 18.
It was one of the highest single-incident death tolls since the beginning of Mexico’s raging drug war, which has claimed nearly 25,000 lives from the time President Felipe Calderon launched a military-led offensive against powerful narcotics cartels in December 2006.
The dead identified by Sunday afternoon were in their 20s and 30s, some related to one another, according to the prosecutor’s office for the state of Coahuila, where Torreon is located. Coahuila borders Texas but, while plagued with the same violence terrorizing other border states, has received less publicity.
Authorities confirmed the number of dead and said some of the injured were in critical condition.
Pictures from the scene showed toppled white plastic chairs, scattered musical instruments and cups, plates and shoes strewn on a blood-splattered floor alongside a tented pool. Empty beer bottles were lined up on tabletops, and bullet holes punctured the walls.
“The party was ongoing . . . when gunmen arrived in several vehicles, disembarked and, without uttering a word to those in attendance, opened fire,” Jesus Torres, state attorney general, said in a statement.
The assailants fled.
Investigators recovered 122 spent shells from high-velocity assault rifles.
Many of the partygoers at the event that began Saturday evening were attracted by an invitation that appeared on Facebook, according to reporters at the Torreon edition of Milenio newspaper and television. The posting included directions and a map.
Organizers of the party were a gay group, Milenio said, but the invitation specifically said the event was open to all. Although that raised the possibility of an anti-gay hate crime, most speculation centered on drug traffickers as the assailants.
Violence has surged in Coahuila, a coveted smuggling transit point, and neighboring states as the longtime dominant Gulf and Sinaloa cartels battle the paramilitary Zetas.
In May, gunmen killed eight people at a bar in Torreon. Later that month, a television station and the offices of a local newspaper came under fire.
Across northern Mexico, there have been increasing reports of mass shootings at parties, bars and rehab clinics. In the worst such massacre this year, gunmen raided a drug-rehab center in the northern city of Chihuahua and killed 19 people last month. In January, gunmen barged into a private party in the border city of Ciudad Juarez and killed 15, many of them high-school or university students. Relatives say the January attack was a case of mistaken identity, while state officials claim someone at the party was targeted, although they have not said who it was.
Officials say 24,800 people have been killed in drug-gang violence since Calderon declared war on the cartels, deploying soldiers and federal police to fight traffickers in their strongholds.
The Associated Press contributed to this report.
