Police are hunting for a man wearing a pink raincoat who may have fired shots at people protesting outside parliament during the violent clashes on Tuesday.

Police said the man was believed to be a guard of the People's Movement protesters and is suspected of having shot at people on Thahan Road.

Six people suffered gunshot wounds during the clashes on Tuesday, which involved police, anti-government protesters and pro-monarchy demonstrators. Police used tear gas and water cannon on demonstrators but denied using live rounds.

Some in the crowd were shot, according to medical workers, but it was unclear who opened fire. A photo of the man wearing the pink raincoat aiming what looked like a weapon at the protesters was shared on social media.

Meanwhile, Labour Minister Suchart Chomklin on Thursday denied any links with a group of yellow-shirt demonstrators who fought with pro-democracy protesters outside parliament.

The yellow-shirt protesters were said to have travelled from Chon Buri, which is Mr Suchart's political stronghold.