A man, who asked not to be named, whose car has Phang Nga licence plates complained that he was insulted then asked to leave a petrol station in Ban Na San district in Surat Thani.

"It's because Phang Nga people let the TRT candidate win the MP seat," he said, quoting the station attendant's reason for not serving him. A number of similar incidents took place last year after Kris Srifa won the only TRT MP seat in the South from 52 candidates.

Kris also won more than 20 per cent of the vote on Sunday, meaning he will probably retain his seat for a second term when the result is confirmed.

News agencies in Nakhon Si Thammarat carried similar reports, where Phang Nga residents claimed they had been refused service at many petrol stations for the same reason.

In Phatthalung, six men were injured when a drunken brawl ended in gunshots. The fight started when a man from the Thai Rak Thai stronghold of Chiang Mai was forced by his companions to speak the southern dialect but failed.

Jankaew Sakda was shot and seriously injured along with two other men who were drinking at a funeral held in Pa Bon district.

Police are trying to find the gunman and three other men who fled the scene after the shooting.

Witnesses told Pa Bon police that the six men, including Jankaew, were drinking and discussing politics and tempers became frayed.

Preecha Kingthongmark, of Phatthalung, who was also shot and injured, reportedly forced Jankaew to try speak the southern dialect. The six men then had a fistfight after Jankaew failed to speak the dialect satisfactorily.