A deadly clash between Thai security forces and drug traffickers left 15 people dead on the Thai-Myanmar border, according to Thai media reports.

The Royal Thai Army said in a statement that on the night of December 16, a patrol of Thai special forces encountered a group of backpackers carrying drugs in Mae Flong District, Chiang Rai Province, in northern Thailand. The smugglers resisted arrest and exchanged fire with the troops for about five minutes. The next morning, the soldiers searched the area and discovered 15 corpses, along with 17 backpacks containing more than 2.04 million pills of stimulants.

The statement did not identify the nationality of the smugglers. The AFP news agency reported that the incident occurred near the Golden Triangle, a notorious hub of drug trafficking for decades.

A Thai military source told AFP that the 15 suspects were not confirmed to be Thai citizens.

The Nation, a Thai news outlet, reported that the Pha Muang Task Force, a mobile unit of the Thai army, spotted the smugglers crossing the border from Myanmar into Thailand on Saturday night. When the troops asked them to stop and show their IDs, they opened fire. The troops returned fire and a fierce gun battle ensued.

The Nation also reported that the troops found more than 13 backpacks at the scene, but they did not reveal their contents.

The report added that there have been several shootouts between Thai security forces and drug smugglers in the forested hills along the border with Myanmar. In September, a police officer and a smuggler were killed in one such incident.