Mexico City  - State police in the northern Mexican state of Baja California found a tunnel under the border between Mexico and the United States that was used by drug traffickers to introduce illegal substances into the United States, the authorities said Tuesday.

The tunnel was 1.5 metres tall and had lighting and ventilation systems, an elevator and air conditioning, said police director Juan Miguel Guillen Gutierrez.

The entrance to the tunnel was some 60 metres from the border line and went 6 metres deep. The structure was 120 metres long.

Police went to the house following an anonymous tip, and they arrested eight people allegedly linked to the drug trade in the house where the Mexican entrance to the tunnel was found. (dpa)