Thai authorities seized more than 18 million meth pills in the drug-riddled "Golden Triangle", a senior military official said Monday, following deadly anti-trafficking operations in the border region.

The Golden Triangle -- a lawless wedge of land intersecting China, Myanmar, Thailand and Laos -- is the main base of operations for Southeast Asia's highly lucrative methamphetamine trade.

Attempts to crack down on the drug's influx into Thailand have resulted in massive seizures and left at least 15 alleged smugglers shot dead in the country's north since the start of November.

The latest bust occurred in Chiang Rai province on Sunday night after authorities received a tip-off that smugglers were active in the area, later pinpointing two suspicious cars.

"We found and seized bags... all were methamphetamine, about 18.76 million pills," commander Vichit Wongsang said in a press conference streamed live on Facebook.

Bags taken in the operation were branded with "999", a trademark associated with Myanmar drug lords.

He added that in the past two months, northern army units had seized about 50 to 60 million pills in total.

The operation comes almost two weeks after police in Chiang Rai killed a smuggler in a shootout while two others escaped into the night.

Police said they found 15 million tablets in bags, also marked "999", in that incident.

Traffickers in the region often employ smugglers from local hill tribes but much less is known about the major players involved and the vast amounts of product that makes it through.

© AFP