Seven prison officers have been charged in the Joaquin “El Chapo” Guzman jailbreak, the office of Mexico’s attorney general said Friday. The government did not disclose their identities.

The officials were “driven to a federal detention centre” after being charged, a source told Agence France-Presse. Following Guzman’s escape from a maximum security prison last Saturday, prosecutors reportedly detained 22 prison officials for interrogation, including the facility's director. However, it remained unclear whether the director was also among those charged.

Guzman fled the high-security prison through a 1-mile tunnel from an opening in the shower area of his cell -- his second jailbreak in 15 years after his first arrest in 1993. Guzman had escaped from a maximum security jail in Jalisco state in January 2001.

The latest escape of the Sinaloa drug cartel kingpin became a major concern for Mexican President Enrique Pena Nieto as his administration had hailed Guzman's arrest last year as its biggest achievement. After returning from a trip to France, Nieto said Friday that the fugitive’s escape led to widespread frustration and that only his recapture could undo the damage, Reuters reported.

Also, a Mexican government spokesman reportedly said that the United States had sought the extradition of Guzman nearly two weeks before his escape.

Amid the ongoing massive manhunt, Mexican authorities issued a “maximum alert” to some 8,200 federal police officers in every state. They are also searching hotels, hospitals and funeral homes, and private flights in airports across the country. About 100,000 leaflets with Guzman’s photo were distributed to highway toll booths while 48 canine teams inspected passenger and cargo vehicles. Security officials have reportedly established 101 checkpoints on main highways across Mexico. 

On Tuesday, the Mexican government also announced $3.8 million reward for information leading to Guzman's capture.