The acting head of the US Drug Enforcement Administration has warned that an alliance between Chinese and Mexican traffickers is importing vast quantities of fentanyl, a drug described as being 30 or 50 times stronger than heroin.
Chuck Rosenberg made the comments at a press conference held by the DEA in Virginia, as fentanyl continues to cause panic across the United States.
The powder-based drug, an opioid like heroin, is primarily a pain medication but is often used recreationally and has been linked to a growing number of deaths.
Rosenberg said that Chinese criminal gangs usually send only small quantities of fentanyl, less than a kilogram, direct to the United States. However they export much larger quantitites to Mexico and local cartels then send it on to the US through established routes and networks, especially in the north-east and south-west of the country.
Key target areas for the traffickers reportedly include California, Arizona, Pennsylvania, New York, New Jersey, Massachusetts and New Hampshire.
The number of deaths attributed to fentanyl and tramadol, another pain relief drug, have risen 79% in recent years, having passed 5,000 in 2014.