NAKHON PHANOM: A total of 560 kilogrammes of dried marijuana were seized and four suspects arrested in recent actions, the Mekong Riverine Unit said.
The dates and times of the operations were not disclosed.
MRU commander R/Adm Charaskiat Chaiyan told reporters on Sunday that a team searched a house in the Kok Tong community in the Muang Nakhon Phanom Municipality and arrested four young men, aged 17-24.
They seized 140 packages of dried marijuana, each about one kilogramme, and about 100 grammes of crystal methamphetamine. The marijuana was in boxes ready to be sent via delivery services.
Also impound as evidence were a Mitsubishi Triton pickup and a 9mm Beretta semi-automatic pistol with 35 rounds of ammunition.
A subsequent search of a delivery company office in Muang district found 20 boxes containing marijuana, about 20kg.
Another MRU team seized 404 slabs of dried marijuana, about 1kg each, from the bank of the Mekong river in tambon Tha Champa of Tha Uthen district.
The drugs had been smuggled across the river from Laos and left on the river bank for collection. No arrests.
More than two tonnes of smuggled dried marijuana were seized during the past month, R/Adm Charaskiat said.