Myanmar authorities have seized more than 200 kilograms (440 lbs) of heroin on their side of the infamous "Golden Triangle", arresting three men armed with guns and a grenade launcher, police said Wednesday.
The haul, worth around $20 million, was made on Tuesday afternoon in a town in eastern Shan State bordering Thailand as a part of a wider crackdown on drug trafficking across the country.
"More than 200 kilograms of heroin in the form of 665 blocks were seized from a truck," a senior anti-drugs squad police officer told AFP on condition of anonymity.
"We arrested three men with two pistols and one M79 grenade launcher," he added.
Myanmar is the world's second-largest opium producer after Afghanistan and Southeast Asia's biggest synthetic drug maker, according to the United Nations Office on Drugs and Crime, which has warned that criminal activity threatens the nation's stability.
Myanmar police officers told AFP that the drug problem has been growing around the country, warning that inadequate assistance from the state and international community could lead to the problem deepening.
"The President has instructed us to control the situation by arresting drug traffickers," the police officer told AFP.
"Even though we are tackling them, the problem is getting worse."
Drug production in the country's war-torn borderlands has surged in recent years, particularly the manufacture of methamphetamine tablets in hidden jungle laboratories.
Residents in border towns say the pills can be bought readily at roadside stores.
The "Golden Triangle" region, covering parts of Laos, Thailand and Myanmar, was formerly one of the world's top producers of opium and heroin, until the emergence of Afghanistan as a hub.