The Mexican Attorney General's office announced it had arrested seven officials over suspected involvement in the jail break of drug kingpin Joaquin (El Chapo) Guzman.
Guzman's escape last Saturday from a maximum security prison through a mile-long tunnel built into his cell was a profound embarrassment for President Enrique Peña Nieto, raising pressure on the government to do more to battle public sector corruption.
As the tunnel surfaced in a blind spot in the cell behind a shower wall, government officials said it could only have occurred with the collusion of prison guards and officials, and that Guzman's helpers must have seen the building's plans.
The government dismissed the head of the prison and questioned more than 30 prison officials over the escape. It did not name the seven people who were arrested and a government spokesman could not immediately clarify the matter.
Federal police in Mexico put reward notices on their vehicles announcing a reward for information leading to the capture of notorious drug kingpin Joaquin (El Chapo) Guzman.
Peña Nieto, returning from a visit to France, on Friday acknowledged the escape had caused widespread frustration and that the only way to undo the damage was to recapture Guzman.
Separately, the government said the United States had requested the extradition of Guzman about two weeks before the breakout took place.
That news hinted at a U-turn by the government, because the previous attorney general, Jesus Murillo had said in January the country had no plans to hand him over.