The more than 100 inmates who escaped this week from a prison in the Mexican border city of Piedras Negras walked out through the main gate, a senior official said Wednesday.

The escapees "did not leave through the tunnel," Coahuila state Public Safety Secretary Jorge Luis Moran said, contradicting his own earlier statements.

Statements from three fugitives who were recaptured Wednesday indicate the mass escape took place via the prison gate, the secretary said, adding that "there was a betrayal by (prison) personnel."

Sixteen prison employees remained in custody Wednesday on suspicion of aiding the escape.

Authorities began offering varying accounts within hours of the initial report about Monday's escape from the prison in Piedras Negras, a city of some 150,000 people just across the border from Eagle Pass, Texas.

The number of escapees was first revised downward, from 132 to 129, and then adjusted upward to 131, including the three apprehended on Wednesday.

Investigators originally said the inmates dug a tunnel to the prison's north wall, made their way into the yard and cut through a fence.

The tunnel was described as being about 30 meters (nearly 100 feet) long and about 3 meters (nearly 10 feet) underground.

Moran did not mention the tunnel in his comments on Wednesday, though he said the testimony from the three recaptured inmates confirmed suspicions that the Los Zetas drug cartel organized the mass breakout.

"They (the three inmates) were recruited by that group, which is waging a war in Tamaulipas and other states of the republic," Moran told ForoTv.

The Zetas, originally a band of army deserters working as hired guns for the Gulf cartel, went into the drug business for themselves several years ago and have become embroiled in vicious turf battles with their former partners and other criminal outfits.

Monday's prison break was the biggest in Mexico since Dec. 17, 2010, when 141 inmates escaped from a penitentiary in Nuevo Laredo, a border city in the northeastern state of Tamaulipas. EFE