BANGKOK (AFP) - Nearly 200 migrants have been detained in a single southern Thai province ever since a network of jungle prison camps run by people smugglers was uncovered there, police said Saturday.

Spurred by Thai junta chief Prayut Chan-O-Cha's calls to end the grim trade within 10 days, police have launched an operation against smugglers in Songkhla, a province neighbouring Malaysia criss-crossed by trafficking trails.

Observers say the belated move against gangs long known to have operated with the help of corrupt officials has put smugglers on the backfoot.

As a result scores of desperate Bangladeshi and Myanmar Rohingyas have been abandoned as their gangmasters go underground.

"So far there have been 199 victims found in Songkhla province alone", regional police official Major General Puthichart Ekachant told AFP on Saturday.

Of the migrants discovered 74 were Rohingyas from Myanmar and 58 were Bangladeshis while the background of 67 more was yet to be determined, he added.

Authorities have been at pains to show Thailand is serious about tackling people-smuggling after years of accusations that they turn a blind eye to - and are even complicit in - the trade.

Four secret jungle camps have now been found in Songkhla since last weekend, alongside 33 bodies in various states of decay, Puthichart said, with many pulled from shallow graves.

Tens of thousands of Rohingya Muslims have braved the dangerous sea crossing to southern Thailand from Myanmar in recent years, with many headed for Malaysia and beyond.

Many die at sea. But of those that make it, large numbers end up in remote camps across southern Thailand where investigators believe traffickers demand up to US$3,000 (S$3987) from relatives and friends for their release.

Others are sold on to Malaysia, according to activists working to expose the trade.

The exodus of Rohingya - described by the UN as one of the world's most persecuted minorities - has followed deadly communal unrest which broke out in western Myanmar's Rakhine state in 2012.

Rohingya living in Bangladesh, as well as Bangladeshis, have also been trafficked to Thailand, after being duped with fake job offers or even drugged.

Last year the US relegated the kingdom to the bottom of its list of countries failing to tackle modern-day slavery.

The next State Department report on human trafficking is expected imminently and Thailand has lobbied Washington against its inclusion in the lowest tier.

National police spokesman Prawut Thavornsiri told AFP 36 arrest warrants have been issued during the latest crackdown.

Puttichart said 11 arrests had been made so far.

More than 50 police officers, including senior officials, have also been transferred from their posts for complicity or failing to act on the trade.