LAGOS, Nigeria (AFP) — Nigeria’s anti-drug agency said Thursday it had arrested two men for allegedly operating a methamphetamine laboratory, the latest in high-profile crackdowns on drug operations authorities say are linked to Mexican cartels.

It is Nigeria’s fourth bust of large-scale production labs since May — all linked to Mexicans — raising concerns that Latin-American cartels are establishing roots in Africa’s most populous country to produce and ship out methamphetamine.

West Africa has emerged in recent years as a transit point for drugs from South America to Europe, mostly cocaine.

An AFP investigation published on Thursday revealed that Mexican cartels are setting up operations in parts of Africa — including South Africa and Nigeria — to feed the demand for drugs in Europe, Southeast Asia and Oceania.

The National Drug Law Enforcement Agency (NDLEA) said in a statement that Chukwu Obumneme Christopher, 45, and Chukwu Georginus Monday, 60, operated the lab in partnership with “notorious Mexican drug cartel member” Rodriguez Villanueva.

“Vast quantities of precursor chemicals” were discovered at the makeshift lab in Obeagu town in Awgu district of southeastern Enugu State, Femi Babafemi, NDLEA spokesman, said.

The trial of the two, who have already appeared in court, continues on October 21.

Villanueva, who has left the country, and two other Nigerians, who are still at large, were also charged in court.

At least five Mexicans have been arrested in Nigeria since May in connection with meth lab operations, Babafemi told AFP.