A four-square-mile perimeter near the East Hidalgo Detention Center in La Villa has been lifted as the search goes on for six escapees.
One fugitive is former McAllen policeman Francisco Meza-Rojas, who was held on drug charges.
The other five are illegal immigrants from Mexico who are believed to be members of a violent drug gang.
Authorities say the men last night overpowered a guard, then cut through fences at the unit.
The minimum-to-maximum security unit is operated by LCS Corrections Services of Lafayette, Louisiana.
Vice President Richard Harbison says the facility has never had a breakout through the fence.
Authorities determined that the inmates gained access to several exit doors after overpowering a guard with a homemade knife and locking him in a room.
The guard wasn't hurt.
No alarm was sounded.