SURIN: A male teacher and three women were arrested on charges of procuring underaged girls for prostitution -- with the youngest being 14 -- following a raid on three karaoke bars in Sikhoraphum district.

A Department of Provincial Administration (DPA) special operations team led local officials in raiding the three karaoke bars along Highway 226 in Sikhoraphum district of this lower northeastern province on Thursday night.

The raid followed an allegation by the anti-human trafficking organisation Lift International that Leo Karaoke and Nad Phob Karaoke, located alongside the highway in tambon Ra-ngae and Don Kaew Karaoke in tambon Yang, were procuring girls to provide sex services to customers.

The raids were launched late on Thursday night which surprised the customers who were asked to leave the karaoke bars.

Officials rounded up 19 sex workers from the three bars. They included seven aged below 18, with the youngest being 14. There was also one male staff member at one of the bars.

Officials also arrested the operators of each bar and charged them with procuring girls for the flesh trade, persuading girls aged under 15, and also under 18, to provide sex services, operating venues offering sex services and helping people carry out sexual molestation even though the acts were carried out with the consent of sex workers, and assisting children to act inappropriately.

According to the team's Facebook page, Leo Karaoke was run by Mr Yutthasak, 51, a local schoolteacher and Ms Khanittha, 19. Their surnames were not given.

There were five girls working at their bar, with the youngest aged 15. The girls served beer and entertained customers and there was a service charge of 80 baht, which was split evenly between the waitress and the bar.

Customers could also buy sex services from the girls for 2,500 baht per session, of which the bar kept 500 baht. Mr Yutthasak and Ms Khanittha drove the car taking the sex workers and customers to a nearby resort.

Nad Phob Karaoke was operated by a woman called Patcharaporn, 41, whose surname was also withheld. The bar had eight sex workers, the youngest also being 15. Their service charge was 100 baht per drink with the bar receiving 40 baht and the waitress 60 baht. Its staff also provided sex services, at a price of 1,500, 1,800 and 2,300 baht depending on the girl's age. Ms Patcharaporn would keep 300 baht for each payment made for a girl.

Lastly, Don Kaew Karaoke was run by a woman called Pornwipa, 28. The bar had seven staff with the youngest being 14 years old. It charged 70 baht for beer, with the bar getting 50 baht and the rest going to the girls. Customers could also buy sex services for 1,500 baht per session. The bar would keep 300 baht, according to the team's Facebook page.

Narong Thipsiri, director of the DPA's law enforcement centre, said human trafficking was a major problem as it violated human rights, laws and morality. If offenders were government officials or state officials they would face harsher punishment, he said.