STORY: Manzanillo, on Mexico's Pacific coast, is the country's largest port. It receives almost 60% of the shipping containers that arrive in Mexico daily.
And Mexican navy officials who run the facility are increasingly worried about the flow of unregulated chemicals into the port that could be used to produce synthetic drugs such as methamphetamine and fentanyl.
That's according to four navy officials who spoke to Reuters on condition of anonymity.
This port protection officer said that Manzanillo, because of its strategic position, is a window to ports in Asia, South America and North America.
The officials said they have seen an increase in imports of dual use chemicals, mostly from China, that are used to manufacture legal items such as food, perfume and pharmaceuticals. But the same chemicals also double up as precursors to synthesize meth and fentanyl.
One naval officer said large quantities of these "dual use" chemicals have been found in clandestine drug labs.
An officer at Manzanillo port pointed to a shipment from China that was seized in January with 88 metric tons of glacial acetic acid, an unregulated chemical used in meth production.
Last month it was impounded because the importing company could not prove the ownership.
Another Navy official said many seized substances are imported by companies in the Mexican states of Jalisco and Sinaloa.
Those are the home bases of Mexico's two biggest drug trafficking groups, the Sinaloa Cartel and its rival, the Jalisco New Generation Cartel.
U.S. officials say Mexico produces most of the fentanyl that ends up on American streets.
Mexican cartels have long produced methamphetamine for the U.S. market, but in recent years they have increased exports to Australia, the Netherlands and China.
The naval officers told Reuters the country needed new regulations on these chemicals.
The Mexican government did not immediately respond to a request for comment.
