BOGOTA, Colombia (AFP) — Colombian guerrillas fighting the government and rival armed groups on Tuesday threatened a major United Nations (UN) biodiversity summit to be held later this year in Cali, the city closest to territory they dominate.

The 16th meeting of the Conference of the Parties (COP16) of the Convention on Biological Diversity “will fail even if they militarize the city with gringos (Americans),” the EMC armed group wrote in a message on X addressed to President Gustavo Petro.

Being granted COP16 host status was a major coup for Petro, Colombia’s first-ever leftist president who campaigned on an ambitious conservation and climate change program.

But the EMC in its message Tuesday accused him of overseeing “civic-military plans disguised as development actions” in areas under its influence.

The warning came on the same day as the military vowed to clamp down on an EMC faction that recently walked out of peace talks with the government.

The EMC, or Central General Staff, is a group of dissidents that rejected the peace deal signed in 2016 by the FARC guerrilla movement, which subsequently disarmed.

Some 3,500 EMC are estimated to remain in arms and are involved in the drug trade and illegal mining, as well as fighting both the military and groups competing for trafficking routes and territory.

They are particularly active in the departments of Valle del Cauca, of which Cali is the capital, and Cauca — both in the main coca-growing southwestern region of the nation, which is the world’s largest cocaine producer.

COP16 host Cali, associated with a particularly violent chapter of Colombia’s deadly drug conflict, has been facing a new wave of brutality as it prepares to host the 21 October to 2 November COP meeting.

The event hopes to attract some 12,000 delegates and exhibitors, as well as heads of state, to one of the world’s most biodiverse countries.