PATHUM THANI - A man selling firearms online was arrested and guns and ammunition seized during a raid on a townhouse in Khlong Luang district shortly before dawn on Thursday.
A combined force of police, soldiers and local officials, armed with a search warrant, raided the three-storey townhouse at Phra Pin 7 housing estate in tambon Khlong Nueng.
They found about 20 unregistered guns, some of them modified, 500 rounds, an amount of marijuana and pipes for smoking drugs.
House owner Kritsana Phutkitpinyo, 25, was detained and taken to Khlong Luang police station for interrogation.
Pol Col Ritthinan Puipanthawong, chief of Khlong Luang police, said they had been closely watching for people selling weapons online. Mr Kritsana was found to be involved in illegal sales of firearms.
The investigation would be extended to find the source of the guns, and the other people involved in this trade, said the Khlong Luang police chief.