The recent arrest of a 17-year-old girl who procured an underage girl for an Indian tourist in Pattaya highlighted the recent crackdown on prostitution and human trafficking rings whose perpetrators and victims are getting younger, according to police.

Police have vowed tough action against both procurers and customers who are increasingly resorting to Facebook and Line to match underaged victims with customers.

"This is our new policy [on solicitation involving minors]," deputy Tourist Police Bureau chief Surachate Hakparn said, urging that people who buy sex services are treated as offenders and also face human trafficking charges.

Police have launched sting operations and widened their investigation to cover many provinces.

On June 5, police nabbed a young procurer and an Indian customer in Pattaya. Three days later the investigators traced the gang north to Nakhon Sawan where they arrested a pimp and six other customers.

So far, the police have pressed three charges against Parmod Kumar who allegedly paid for sex with a 14-year-old girl. The 47-year-old suspect is charged with depriving the girl of parental care and raping her.

According to Pol Maj Gen Surachate, Mr Kumar could face an additional charge of human trafficking.

"Underaged prostitution and human trafficking-related charges can put offenders behind bars for up to 20 years," he said.

According to investigators, the 14-year-old victim is a native of Ubon Ratchathani. She was lured through a Facebook page by the older girl who ran a sex service ring in Pattaya. The victim was first told to stay with "other girls" at a hotel before she was sent to Mr Kumar.

The Indian tourist paid the girl 5,000 baht and the procurer took a 1,000-baht cut.

The victim later escaped and returned home, but the procurer went after her, demanding she return to Pattaya. She accused the victim of stealing her money, prompting the victim's family to file a police complaint which eventually led to the arrest of the procurer and the Indian customer.

Pol Maj Gen Surachate said many victims of the underage prostitution rings based in popular tourist destinations come from the Northeast.

These destinations include Hat Yai, Koh Samui and Phuket, where nightlife venues and illegal brothels are common.

In another underage prostitution case, police found eight young victims, including a 13-year-old, offering sex services in Nakhon Sawan. This came after the arrest of a teenage boy who procured underage girls for six customers -- Kwanchai Phromthong, 30, Yingsak Prasoetsang, 61, Parinthon Sirichoi, 31, Suphot Wgongdi 44, Winai Buawat, 34, and Anek Butsing, 34.

The customers were charged with raping minors in addition to other charges, including human trafficking, which were also pressed against the teenage boy.

The crime was exposed after police obtained information about the suspicious behaviour of some junior high school students in Nakhon Sawan, who often skipped classes and indulged in lavish lifestyles, Pol Maj Gen Surachate said.

A police investigation led to the discovery of the 13-year-old girl, who had been lured into providing the illegal sex services.

It is unclear if the high school and Pattaya cases are linked.

The police later expanded the investigation which led to the arrest of a male suspect who procured eight teenage boys for prostitution. The procurer and the boys came into contact through Facebook and Line.

An initial check found at least six people had bought sex from the boys, Pol Maj Gen Surachate said.

"We've sought court warrants for the arrest [of the procurer and the customers] on human trafficking charges," he said. 

"These cases show the pattern behind sex services is changing," he said, noting that victims' profiles are frequently posted on popular social networking sites, leading police to undertake more online surveillance.

Over the past three months, police found up to 700 websites offering sex services in Thailand, Pol Maj Gen Surachate said. The Digital Economy and Society Ministry has been asked to close and block access to these websites, which are based both here and abroad.

The deputy Tourist Police Bureau chief insisted the police will continue a sweeping crackdown on both the sex service gangs and their customers.

Thailand, whose situation is being monitored by the international community, must "earn credibility in solving human trafficking," Pol Gen Surachate said.