http://kvoa.com/Global/story.asp?S=4045211&nav=HMO6

The fourth drug tunnel in a year and a half has been discovered within 200 yards of the port of entry in Nogales.

The drug tunnel has now been filled in by city crews.

It was found Thursday night when Border Patrol agents on bike patrol were riding on the sidewalk when they noticed part of the pavement caving in.

Whoever was constructing the tunnel only made it as far as 6 feet into the U.S.

It's about 4 feet high and measures 3 feet in diameter.

Agents say they foiled the smugglers attempts to bring illegal drugs and people into the country.

Agent Jose Maheda says, "Ever since we became part of Homeland Secuirty, intelligence says drug smugglers and people smugglers intermingle."

Federal agents say their efforts to protect the border are paying off. "W e're seeing them use more crude efforts to build tunnels and we are pushing them towards the down town area to get their drugs and peopole through."

Nogales police officials say the tunnel goes from the fence, across the street, and the pavement caving in is also visible. They also say they believe the tunnel starts somewhere in one of the buildings.

Agent Maheda says, "Last year and a half, four tunnels within a mile from the port of entry have been located.