Police on Friday used water cannon against a large crowd at the Pathumwan intersection in central Bangkok.
Jets of water, some of it dyed blue, were sprayed from trucks parked behind hundreds of riot police advancing toward a crowd estimated at 2,000 at around 6.30pm.
Some protesters said the water contained a chemical that made their eyes hurt but its exact composition could not be confirmed.
The demonstrators tried to push back. Many held locked umbrellas in front of them, a tactic learned from protesters in Hong Kong. Others threw water bottles at the officers. Some spectators on the skywalk dropped their umbrellas to the protesters so that they could protect themselves.
Police ordered the crowd to disperse immediately. Media members were reportedly told not to live-stream images of the police action.
Some protesters began building barriers at the intersection to prevent officers from moving in. Others chased away police officers and chanted “get out … stop harassing people”.
The police said that four riot-control officers and 11 protesters were injured in the confrontations.
By 7.30, most of the crowd had begun to leave Pathumwan, after protest leaders told them to go home and prepare for the next event.
A small group of activists remained outside Siam Center but they were chased away by riot police with batons and shields. An unknown number were arrested.
Organisers vowed to stage another rally on Saturday to press for the ouster of the Prayut Chan-o-cha government, but they are keeping the location a secret.
