The two walked out of the prison's main gate in Culiacán wearing uniforms.

They were escorted by two guards believed to have been in their pay who also drove the getaway cars.

Officials said Carlos Salmón and Julián Grimaldi were considered "highly dangerous" inmates and had been held in special cells to prevent them from escaping.

They had originally been held in federal prisons, which have higher levels of security, but were returned to the Aguaruto prison in Culiacán after they had successfully appealed against the order to hold them in federal penitentiaries.

• A history of dramatic prison escapes

Grimaldi was arrested in February and is accused of being a financial operator for the Sinaloa cartel, one of the most powerful criminal organisations in Mexico.

He is also suspected of having taken part in an ambush in September 2016 during which five soldiers were killed.

Salmón was arrested two years ago on suspicion of being the leader of a gang of hit men. He is accused of carrying out an attack on a police convoy in 2012 in which seven officers were shot dead.

The two prisoners managed to sneak past six security checks during their escape.

There have been a number of high-profile prison escapes in Mexico in past years, the most famous being that of the leader of the Sinaloa cartel, Joaquín "El Chapo" Guzmán.

Guzmán escaped from a maximum security prison near Mexico through a tunnel in 2015. He was recaptured six months later and has since been extradited to the US.