TIJUANA, Mexico - Days after a wild, deadly shootout between drug cartel gunmen and Mexican police and soldiers, authorities have uncovered what they say is a clandestine training ground for cartel assassins, complete with an underground target range that investigators believe went undetected for months.
The house was raided late Saturday night by heavily armed federal police. They found two armored pickups parked at the home, along with two other vehicles that had hidden compartments, authorities said.
At ground level, the two-story green-and-white hillside house in the Independencia section of Tijuana included a machine shop for assembling and repairing weapons. Parts of disassembled pistols and rifles lay on the floors.
Below ground was a target range measuring about 50 feet long by 21 feet wide and 8 feet high, its walls and ceiling lined with gray soundproofing material and equipped with a fan to ventilate the gun smoke. Thousands of spent cartridges - perhaps as many as 30,000, according to authorities - were collected in bins along one wall.
Bullet-riddled targets lay on the floor.
The discovery came two days after last Thursday's firefight in the La Mesa district of Tijuana between gunman and police at another house where six murdered kidnap victims were eventually found.
The gun battle was part of a particularly bloody period in Tijuana. Earlier last week, three police officers, including two high-ranking commanders, were shot to death. One was attacked in his home, where gunmen also shot his wife and their young daughter to death.
Some analysts say the federal government's crackdown on organized crime has prompted the gangs to respond violently.
Both the La Mesa house and the training center in Independencia are believed by investigators to have belonged to the Arellano Felix drug cartel,based in Tijuana.
Independencia is one of the older neighborhoods in the city, sprawling across steep hills and canyons, a working-class place where homeowners build their own add-ons.
A false bathroom hid the entrance to the underground target range, said Agustin Perez Aguilar, security spokesman for the state of Baja California.
"The shower, the toilet, the sink where you wash your hands, none of it actually worked," he said.
Although gunmen had been using the place for months, neighbors apparently were none the wiser, Perez said.
The house, on Avenida Reforma, is directly across the street from an elementary school.
"Nobody heard anything, never," Perez said.
Similar training centers for drug cartel gunmen have been found elsewhere in Mexico, Perez said, usually in homes rented from legitimate owners.
"They're usually very good tenants," he said. "They're very quiet and they usually pay very well, never a problem."
Monday, authorities allowed journalists to tour the house. Squads of masked federal police officers in combat boots, bulletproof vests and armed with automatic weapons guarded the inside of the house, the outside and both ends of the street as reporters climbed down through a hole in a bathroom floor near the garage into the underground shooting gallery.
Authorities urged residents who suspect similar cartel safe houses in their neighborhoods to call police anonymously.
"We are asking people to denounce suspicious places, suspicious cars," Perez said. "If citizens will call us, we can find these places and stop these people."