Investigators on Thursday were trying to figure out how a former police officer facing drug charges and five other federal inmates escaped from a private jail, while the search for the fugitives was expanded far outside South Texas.

"We're looking all over Texas and other states and into Mexico," U.S. Marshals Service Deputy Joe Magallan said.

No more prisoners were being sent to the East Hidalgo Detention Center pending a probe into how the inmates overpowered a guard, slipped through a power-controlled door and cut through a series of fences late Tuesday. The fences included an alarm-equipped electrical fence that apparently wasn't functioning and may have been turned off, Magallan said.

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"Everything's being looked at," he said.

Magallan said tips and reports of sightings were streaming in, but so far nothing had proved substantive. Investigators were questioning relatives of the escapees and trolling fugitives' known hangouts for information. He said officials were following several leads.

The jail remained in lockdown Thursday and there had been "top-to-bottom shakedown" of inmates and staff, said Patrick LeBlanc, co-owner of LCS Corrections Services Inc., of Lafayette, La. LCS is a private company that runs the facility.

He said the fence company was examining the fence system and that LCS was doing a security audit as well as adding more external lighting, security cameras and armed guards around the perimeter.

"We deeply apologize to the community," he said. "Before this issue we were under the assumption we had good security. Sometimes it takes an event to show us that we didn't."

LeBlanc offered a $25,000 reward was for information leading to the capture of 41-year-old Francisco Meza-Rojas, the former McAllen police officer.

Meza-Rojas' trial on federal drug trafficking charges was scheduled to begin Oct. 3. The other escapees were illegal immigrants from Mexico alleged to be members of Raza Unida, a violent drug gang.

Authorities said the inmates gained access to exit doors after overpowering the guard with a homemade knife and locking him in a room, then used "some sort of wire cutter" to breach the fence lines. No alarm was sounded. The guard was not injured.

The fugitives were thought to have split up, Magallan said. Hidalgo County Sheriff Lupe Trevino said in a press release Wednesday that the men were likely picked up in a vehicle on state Highway 107, which runs in front of the facility.

Magallan said search dogs lost scent of some footprints at the highway and of other footprints at a levee near the prison, which was wet, muddy, and thick with high grass.

More than 60 local and federal law-enforcement officers using helicopters and bloodhounds searched Wednesday near the jail, about 20 miles north of the Mexican border. Officers searched door-to-door, residents were asked to stay home, and schools were closed.

The facility is a minimum-to-maximum security unit with 950 beds, about 800 of which are federal. LCS bought the jail about five years ago.