Two Mexican marines were gunned down Monday in pursuit of infamous drug lord Joaquin Guzmán, aka "El Chapo."

Spanish news outlet El Pais reports the shooting occurred in the coastal town of Angostura, in Mexico's Culiacan state. The marines were patrolling the area when their convoy began to take fire.

The Secretary of the Marines said the assailant was identified as Jose Maria Penuelas Rubio, a criminal with a prior record for destruction and falsification of documents. He was killed in the attack as well.

This incident marks the second time in less than a week that an assault has been waged on a special marine operations convoy in the country. On Christmas Day, a separate convoy was attacked in Guzmán's hometown of Badiraguato in Sinaloa.

When the marines called for reinforcements to fight off the attack, the assailants began firing at the military helicopters that came to help. Two of the gunman were killed in the exchange. Afterwards, authorities confiscated a number of military grade weapons, including assault rifles, grenades and munitions.

The marines also located and destroyed four tons of marijuana.

Mexican authorities are focusing their search for El Chapo in a mountainous region known as the Golden Triangle, which sits between the states of Sinaloa, Chihuahua and Durango.

Guzmán escaped from a maximum security prison last July by traveling through a tunnel dug under his cell. In the investigation that followed, dozens of penitentiary officials were arrested in connection with the escape plot.

It is unknown where Guzmán is currently hiding out, but Mexican security forces suspect he may be somewhere in the Sierra Madre mountain range. Other notorious fugitives from the Sinaloa cartel -- such as Guzmán's ally Ismael Zambada García and Rafael Caro Quintero -- are also believed to be hiding in the area.

The manhunt has forced hundreds of locals to flee their homes.