YANGON - MYANMAR authorities arrested more than 300 drug traffickers in November as part of their crackdown on the narcotics trade, state media reported on Friday.

The military-ruled nation insists it is on track to be drug-free by 2014 but for now remains the world's second-largest opium producer.

'Action was taken against 308 people, 250 men and 58 women, in 207 drug-related cases,' the New Light of Myanmar newspaper said.

Myanmar police, customs officials and military seized 71.18kg of opium, 7.6kg of heroin, 0.7kg of opium oil, 4.6kg of low-grade opium and more than 220,000 stimulant tablets, the paper said.

The United Nations' Office on Drugs and Crime has said opium production in Myanmar shot up 46 per cent from 2006 to 2007, blaming high-level collusion and corruption for the rise.

Activists across the border in Thailand say crop substitution programmes for poor farmers have not been successful.

Myanmar's mountainous and lawless border regions once hid vast poppy fields which supplied most of the world's opium well into the 1990s.

Under pressure from governments including close ally China, Myanmar eventually began a campaign in the 1990s to eradicate the crop, and soon Afghanistan took its mantle as the world's top opium producer.

But after a few years of steep decline, opium production in Myanmar has risen once again.

The military-ruled nation, meanwhile, has become a hub for methamphetamine production, with convoys of high-tech trucks ferrying chemicals and mobile laboratories under the cover of Myanmar's dense jungle, experts say.

Last month US authorities said they had frozen the assets of 26 individuals and 17 firms tied to drug trafficking in Myanmar and prohibited US citizens from dealing with them.

The US targeted those linked to the United Wa State Army, the most powerful drug trafficking organisation in southeast Asia, according to the US Treasury Department. -- AFP