Nicaraguan police arrested four people accused of controlling airstrips in southern Nicaragua, used to launch drug flights for Mexican cartels, authorities said. 

The arrests come amid growing concerns inside Nicaragua and Costa Rica about the Tarazanes, a transnational network of drug and gun smugglers drawing increased attention from the security forces.

Police spokesperson Vilma Reyes Sandoval told El Nuevo Diario that the four detainees worked with Mexican and Colombian cartels, and that there may be more arrests in the coming days. She added that there may be a larger group based in Nicaragua, involving Costa Rican, Honduran and Colombian traffickers. Prensa Latina cites an unnamed source that says the group was in fact working with the Familia Michoacana.

The traffickers used a fumigation company as a cover for their drug trafficking, and laundered their profits through real estate and cars. Police seized five aircraft, 21 cars and seven properties during the operation.

There are no indications yet that the detainees worked for the Tarzanes, a league of smugglers operating on both sides of the Costa Rica-Nicaragua border. They are usually linked to a traditional contraband family, headed by Agustin Reyes-Aragon and his six brothers.

The Tarzanes are believed to use rivers and lakes as a smuggling routes for precursor chemicals, cocaine, guns and other logistical supplies. La Prensa reports that the Nicaraguan army is finding increased evidence of their involvement in drug trafficking. Since October, the army has found several go-fast boats loaded with tons of cocaine and a secret air strip near the San Juan river, the group’s traditional smuggling route. Six Hondurans who were arrested while trafficking drugs in southern Nicargua on 1 October are allegedly linked with the group.

Nicaragua has asked Costa Rica for help in combating the group, believed to take refuge in Costa Rican territory.