Arrest warrants have been issued in Thailand for 23 people - including government workers, politicians, a former abbot and an ex-soldier - for alleged sexual offences against underage girls in Chiang Mai.

The warrants were issued after officials rescued three girls aged 13 to 15 from a brothel where they had been forced into prostitution, according to a report in the Bangkok Post.

A total of 25 warrants were issued, including one for a woman at the brothel who is accused of forcing the girls into prostitution.

People who have sex with adolescents aged 15 years or below are considered have committed rape under Thai law, regardless of whether the child is willing or not.

The girls told the authorities that the so-called mamasan contacted clients through the Line mobile-messaging application, reported the Post.

It was reported that those wanted included well-known figures in the Chiang Mai social scene.

Among them were senior ministry bureaucrats, successful businessmen, local politicians and some university lecturers.

Of the group, about a dozen suspects have been arrested.

Among them are Major Kriengsak Maiwong, 60, a former army officer attached to a camp in Chiang Mai, and Pone Sungsiri, 47, a former abbot of a well-known temple in the province.

Major Kriengsak is accused of simultaneously molesting all three girls at a "love hotel" in Chiang Mai's Santitham area, said the Post.

Police apprehended him at his home on Monday afternoon.

He denied the charges during questioning.

Chang Puak police station chief Wachira Karnchanawipada told Thairath Online that Major Kriengsak's relatives posted bail with a surety of 200,000 baht (S$7,800) this morning so that he could prepare to fight the case in court.

The police investigator believed the suspect did not pose a flight risk and allowed him to be released on bail, Wachira said.