BOGOTA (Reuters) - The growing presence of Mexican drug cartels in Colombia and their alliances with local gangs are a threat to the Andean country’s national security, the attorney general said on Thursday.

Colombian authorities have long grappled with the presence of foreign criminal groups like Mexico’s Sinaloa cartel, which buy Colombian cocaine from local gangs and ship it north to the United States and Europe.

“It has been clearly identified by the attorney general’s office, and we’ve informed the national government, of a growing presence of Mexican cartels,” attorney general Nestor Humberto Martinez told journalists. “We have to banish them because they are a threat to national security.”

Colombia, one of the world’s top cocaine producers, has the capacity to produce an estimated 910 tonnes annually. In 2017 authorities confiscated a record 435 tonnes.

The Sinaloa cartel is allied with a 300-member group of dissident former members of the FARC guerrillas, who demobilized last year under a peace deal with the government, Martinez said.

The dissidents are operating near the country’s border with Ecuador, an area well known for cocaine output, and the government is offering a $50,000 reward for information leading to the capture of the their leader.