Between February and April, authorities swooped on labs in Kutkai area of Shan state, seizing nearly 200 million meth tablets, 500kg of crystal meth, 300kg of heroin, and 3,750 litres of methyl fentanyl.

The United Nations Office on Drugs and Crime (UNODC) described the haul as one of the largest and most successful counter-narcotics operations in the history of the region.

“What has been unearthed through this operation is truly off the charts,” Jeremy Douglas, the UNODC Southeast Asia and Pacific representative said in a statement.

The raids unearthed “unprecedented” methyl fentanyl, the sign of a new trend of synthetic opioid production emerging “on a scale nobody anticipated”, said Douglas./.VNA