Three of four Mexican journalists kidnapped last week have been released, according to news reports.

Mexican police raided a drug gang safe house before dawn on Saturday, freeing Javier Canales, a cameraman at Laguna Multimedia, and national television network Televisa cameraman Alejandro Hernandez. Televisa reporter Hector Gordoa was freed on Thursday following negotiations with his captors. However, Óscar Solís, who reports for local newspaper El Vespertino, remains missing.

The freed journalists were being held in the northern state of Coahuila by members of the Sinaloa cartel, Mexico’s most powerful drug trade organization, which is run by Mexico’s top drug lord, Joaquin “Shorty” Guzman.

The journalists had been kidnapped in the nearby state of Durango, also in northern Mexico, whilst covering an ongoing scandal at the prison in the city of Gómez Palacio. The prison’s director, Margarita Rojas Rodriguez, has been arrested following accusations that she allowed inmates to use prison vehicles and weapons to commit crimes. Mexican authorities linked inmates to the massacre of 17 people at a party in nearby Torreon city last week, and found shell casings at the massacre matching those from prison weapons. Inmates are now demanding the director’s reinstatement, Milenio Diario reported.

Speaking after his release, Hernandez told a press conference in Mexico City that he had been constantly intimidated during his ordeal and hit over the head with a board.  “They were trying to have a way to force (networks) to broadcast messages,” he said, according to Reuters.

During their kidnap, the journalists’ TV stations had been forced to broadcast messages from the kidnappers of the journalists. Televisa cancelled a popular news show, Starting Point, on Saturday, in protest of the kidnappings. The screen went blank for the duration of the show.

Security Minister Genero Garcia Luna said the kidnappers fled as police closed in on the safe house on Saturday, and none were captured.

Commenting on the release of the three journalists, Interim Director Alison Bethel McKenzie said: “IPI is extremely glad and relieved that these journalists have been released without any further ordeal or injury.  However, we remain concerned for the whereabouts of the fourth journalist,  Solís, who is still missing. We are also concerned that the perpetrators of this kidnapping remain at large.

“We urge Mexican authorities to bring these abductors to justice.  If the authorities are seen to be ineffective or indifferent, it could give rise to similar abductions.”

Mexico has become the most dangerous country in the world for journalists so far this year, with at least 10 reporters killed in an upsurge in violence sparked by a government crackdown on drug cartels.