Police and soldiers battled gunmen at a hospital in the border city of Tijuana Wednesday in violence that left at least three people dead before the authorities subdued the attackers, officials said.
Shooting first erupted when about seven masked gunmen entered the public hospital and were confronted by a group of state police who happened to be escorting prisoners for routine treatment, said Tijuana Police Commander Jaime Niebla.
Two state police officers and one of the gunmen were killed in the clash, Niebla said.
Red Cross representative Fernando Esquer said he believed the gunmen were trying to free one of the prisoners receiving treatment.
The gunmen holed up in a ward for several hours until dozens of soldiers and federal police stormed in. More shots were heard ricocheting from the building, and it was unclear if there were any more deaths.
Soldiers were seen taking several detainees with their faces covered from the facility.
Authorities evacuated 500 personnel and patients from the hospital's seven floors, taking some to nearby private hospitals. There were no immediate reports of patients suffering injuries.
Officials initially feared that patients had been taken hostage, but Niebla later said there were no hostages.
Mexican gangs have stormed several hospitals across the country in recent years to kill injured rivals or free prisoners.
In January, President Felipe Calderon sent 3,300 soldiers and federal police to Tijuana to hunt down drug gangs.
Dubbed "Operation Tijuana," the initiative was part of a nationwide military offensive, in which Calderon has sent more than 24,000 troops to states plagued by execution-style killings and beheadings as rival gangs fight over marijuana plantations and smuggling routes.
Drug gangs were blamed for more than 2,000 murders nationwide in 2006 and have left a particularly bloody trail in Tijuana, where more than 300 people were slain last year.