Sirinya Sitthichai, secretary-general of the Office of Narcotics Control Board, said the Sisouk network was connected to another narcotics network which was involved with Lao suspect Xaysana Keopimpha.

Sisouk was arrested by Lao authorities last month, while Thai police detained Xaysana at Suvarnabhumi Airport in January.

The latest four cases resulted in the confiscation of 4.41 million amphetamine tablets, 1,514 ecstasy pills and other illegal drugs.

In the northern province of Chiang Rai, Sakchai and Yafahtee Sae Yang were arrested for possession of about 4 million tablets of amphetamine and 100 kilograms of methamphetamine, following the earlier arrest of Nattaphol Nak-kham, who allegedly belonged to the Xaysana network.

In another related case, authorities on Sunday arrested Indonesian Noverdian Suthianshah, who was in possession of 1,514 ecstasy pills, methamphetamines and other illegal drugs in Bangkok following the confiscation of 200 ecstasy pills sent from Austria to Pattaya and another parcel of 100 ecstasy pills sent from Germany to Bangkok.

Both addresses in Thailand were used by the same person, who was identified as Noverdian.

Sirinya said drug dealers were using social media to sell narcotics and international cargo services for delivery into Thailand.

In a third case, Sirinya said five Thai suspects had been arrested in Nakorn Pathom province in possession of about 400,000 amphetamine pills. In a fourth case, a Lao citizen was arrested in the northeastern province of Mukdahan on suspicion of being a member of the Sisouk and Xaysana networks.