MEXICO - Authorities in Northern Mexico showed the tunnel that more than 130 inmates allegedly used to stage a mass prison break this week.

The tunnel is more than 21 feet long and about four meters in diameter. According to authorities after they passed through the tunnel, inmates cut through a chain link fence. Prison inmates reported that men behind the escape were members of the Zetas drug gang and authorities suspect the gang staged the break to replenish it's ranks. A judge has ordered the detention of 16 prison guards and officials in connection with the break.