Police issued warnings and then opened fire on the protester guards with water cannon. Speaking through loudhailers, police then warned protesters to stop stay back 50 metres from the Parliament building. Some protest guards responded to the water cannon by throwing smoke bombs towards the police.
Protesters wear raincoats to protect themselves from police water cannon laced with chemical irritant. Those hit were forced to retreat to wash their faces and eyes.
https://www.nationthailand.com/news/30398098