Mexican police and soldiers have discovered two tunnels in the border city of Tijuana that lead into California.

The tunnels were found in an area of warehouses across from Otay Mesa.

Prosecutors said Monday that one of the tunnels reached to San Diego, California, and the other was unfinished.

Photos from Mexican Attorney General's Office show one of two tunnels found in an area of warehouses in the border city of Tijuana that lead into California

The tunnel was found in an area of factories in Tijuana, hidden behind a fake cinder block and some metal doors

Photos and videos provided to Fox News by the Attorney General’s Office showed wooden steps leading to the tunnels equipped with rails and trolleys.

They were hidden behind fake cinder block and metal doors.

The Attorney General's Office said the tunnels were apparently used by the Sinaloa drug cartel to move drugs into the United States.

Tunnel system: Officials said the system was being used to transport drugs, but would not say what kind

Mexican police have discovered a drug-smuggling tunnel leading from a building in the border city of Tijuana into the United States

The discovery of the tunnel was confirmed Monday by the Mexican Attorney General's Office

It said it found the tunnels after the U.S. consulate in Tijuana determined the tunnels were being reactivated after apparently falling into disuse.

Investigators found similar tunnels earlier this year including one running a half-mile from a Tijuana house equipped with a large elevator to a lot in San Diego that was advertised as a wooden pallet business.

U.S. authorities have reported the detection of more than 75 cross-border smuggling tunnels over the past five years, most of them in California and Arizona.

On rails: This is the tunnel was found in the same area in October, featuring a rail track

Going underground: A four-foot-high tunnel (pictured) found leading from a Tijuana building into San Diego was announced by the Mexican Attorney General's Office in October

A 563-yard tunnel found in October, which had its own ventilation and lighting, was also fitted with rails that could be used to push cartloads of drugs through the three-foot-wide, four-foot-high hole to San Diego.

The tunnel's entrance was located in La Hielera del Aeropuerto, a bottling and ice-making facility close to Tijuana's AL Rodriguez International Airport.