BANGKOK (AP) — Fifteen suspected drug smugglers were killed and about two million methamphetamine tablets seized in northern Thailand near the Myanmar border after a shootout with Thai soldiers, Thai officials said.

The clash, which occurred Saturday night, came after the local army received a tip that there would be smuggling activity near the border in Chiang Rai province, said Phanurat Lukboon, acting secretary-general of the Office of the Narcotics Control Board.

Officers found a group of about 20 people carrying backpacks in the area, Phanurat said on Sunday. After the officers identified themselves and asked to inspect the bags, the group began shooting at them, he added.

The clash lasted around 15 minutes and the Thai officers were all safe, Phanurat said while on a visit to the site where the incident occurred. He thanked the officers for their help in “preventing these awful things from entering our country and destroying our youth.”

Seventeen backpacks made from fertiliser sacks were found with the suspected smugglers and more than two million methamphetamine pills were inside the bags, officials said.

No arrests were made and officials were still working to identify the 15 people killed in the clash and the origin of the drugs, according to the Office of the Narcotics Control Board.

On Wednesday, Thailand announced it had seized 50 million methamphetamine tablets in the western province of Kanchanaburi, also near the Myanmar border. It was said to be a record haul of the drug in the country.

Myanmar has historically been Southeast Asia’s main drug production area in part because of lax security measures in border areas where minority ethnic groups have long been fighting for greater autonomy. Some of the powerful ethnic armed groups there have been heavily involved in narcotics production for decades.

A 2021 military takeover in Myanmar that unseated the elected government of Aung San Suu Kyi triggered armed resistance nationwide, further destabilising the country and contributing to an increase in its drug production.

Last week, the United Nations Office on Drugs and Crime said in its “Southeast Asia Opium Survey 2023” that Myanmar has topped Afghanistan to become the world’s biggest opium producer.

The UN drug agency’s June 2023 report on synthetic drugs in East and Southeast Asia warned that the huge trade in methamphetamine and other illegal drugs shows no signs of slowing down.