Anti-government protesters called off a mass rally outside Bangkok's Ratchaprasong intersection around 8.30pm on Wednesday despite anger over the rejection of the so-called "people's draft" of amendments to the constitution.
Protest leader Panusaya “Rung” Sithijirawattanakul said the next rally will be next Wednesday at the Crown Property Bureau.
Before leaving the area, protesters sprayed water into the Royal Thai Police headquarters and left their mark in a blaze of colour on the compound's fence and nearby roads.
The demonstrators spray-painted the plaque of the police agency.
Earlier, police warned that any attempt to storm their adjacent headquarters would meet with a decisive response.
Protesters began gathering at Ratchaprasong intersection in downtown Bangkok late Wednesday afternoon. The Royal Thai Police headquarters are adjacent to the intersection.
Demonstrators gather at Ratchaprasong intersection in Bangkok shortly before 4pm on Wednesday. (Photo: Arnun Chonmahatrakool)
Pol Maj Gen Yingyos Thepchamnong, spokesman of the Royal Thai Police Office, said on Wednesday morning that demonstrators planned to gather at Ratchaprasong intersection and then move to police headquarters.
Riot police were on standby to cope with the situation, he said.
"Any action that causes damage to government property and barricades is considered a violation of the law... If trespassers destroy government property, we will have to take action in accordance with our authority and duty. I emphasise this," Pol Maj Gen Yingyos said.
Traffic police advised motorists to avoid roads in the vicinity of Ratchaprasong intersection from 2pm. The warning covered Ratchadamri, Rama I and Ploenchit roads.
Bangkok deputy police chief Pol Maj Gen Piya Tawichai said that during Tuesday's demonstrations damage was caused to many government vehicles -- four water cannon trucks, two water tankers, two prison vehicles, three buses, 13 vans, three pickup trucks and three multi-purpose vehicles.
Expensive equipment was torn off the high-tech water cannon trucks, and sand, food scraps and metal put in their engines, he said.
Pol Maj Gen Yingyos said the government vehicles were bought with taxpayers' money. Damaging them would not end the political conflict.
Police would continue to enforce the law, he said.