Bangkok, Thailand (CNN) Authorities in Thailand seized hundreds of kilograms of crystal methamphetamine Tuesday in the largest haul of its type in the country's history.
Lt. Gen. Sommai Kongvisaisuk, chief of the Narcotics Suppression Bureau, told CNN a truck containing 788 kilograms (1,740 pounds) of the drug, was detained by military and police in Chiang Rai province near the Mekong Delta.
Around 10 million amphetamine pills were seized during the same operation. The drugs were hidden inside tea bags and packets of fertilizer and Kongvisaisuk said the "14K" criminal syndicate was behind the banned substances.
In total, the amount of drugs seized on Monday had a street value of $55 million, police said.
The haul follows a series of high-profile raids targeting the drug trade in Thailand, which saw thousands of kilograms of crystal meth, speed and marijuana seized between March 25 and April 1.
But despite the large seizures, the country's drug problem was only growing more serious, Jeremy Douglas, Southeast Asia regional representative for the United Nations Office on Drugs and Crime, told CNN.
"We don't see this ending ... the region has to work together to counter these flows or we will continue to see these seizures and we will continue to see growth in meth production and demand," he said.
Between 2016 and 2017, the amount of crystal methamphetamine seized by Thailand's Narcotics Suppression Bureau grew by more than five times, from 630 kilograms to 4,160 kilograms (1,390 to 9,170 pounds).
At a separate press conference Tuesday, Thai authorities displayed large quantities of amphetamines, marijuana and crystal meth that had been seized over the the past two weeks.
"For over one year, we have seized a large quantity of drugs and it has disrupted supply," Kongvisaisuk told reporters. "However, drug production has not reduced and it has never been stopped."
Eleven suspects were taken into custody during the course of the recent raids.
Douglas said a surge in crystal meth production in Myanmar's autonomous northern regions had resulted in a huge amount of cheap, high-quality drugs flooding into the surrounding region and further afield.
"This stuff is being found in Australia, it's being found in Japan, it's being found all over the place, so essentially that part of Myanmar is becoming the production center for methamphetamine for East and Southeast Asia," he said.
Thailand itself is a huge market for crystal meth, Douglas added, but is also being used very effectively by organized crime groups as a logistics hub.
The UN representative said if the drug trade was to be effectively curtailed in Southeast Asia, countries would have to start working together more effectively and target the source of the drugs itself.
"Police response is highly reactive and they're not getting ahead of this," Douglas said. "There need to be a refocus of law enforcement on organized crime at higher levels."