The multipurpose pavilion of a Yasothon school was partially burned down, while red-shirt supporters in Chiang Mai removed telltale flags from their houses and cars for fear they might be targeted by officials.
In Yasothon's Muang district, the pavilion of Ban Kham Nam Klieung School was set on fire late Sunday night but neighbours managed to extinguish the blaze, saving it from total destruction.
A suspect was seen escaping on a motorcycle, which he abandoned on a road before fleeing into nearby woods.
Police seized the motorbike as evidence to help hunt the suspect down.
Chiang Mai residents took off the red flags they had put in front of their homes and on their cars, especially in San Patong and Phrao districts, where such red flags were reportedly on every house. They said they were taking precautions to ensure their own safety and to prevent bullying by officials.
At 9am, a 200-strong police and Army crowd-control team searched the FM 89.0 Wihok radio station in Chiang Mai's Muang district, which was also the People's Alliance for Democracy Thahanseu Phraracha Group location.
One ping-pong bomb, three makeshift spears, one shotgun loaded with three shells, and 34 bullets were found, but the gun had a legal permit.
Officials said this search was intended to set an equal standard after police had searched their rival red-shirt demonstrators' radio stations. The station was also suspected of airing messages affecting national security by inciting the public. The group's leader Therdsak Jiamkitwattana said the search was a mistake because officials were turning against their ally.
In neighbouring Lampang, police beefed up security at the government office complex.
In Khon Kaen, Bundit Tangprasert, director of the Public Relations region 1 office, said the property damage by red-shirt supporters during last Wednesday's rampage was initially assessed at Bt125.6 million.
In Udon Ratchathani, Governor Amnat Phaka said the legal action against the 48 red-shirt supporters arrested for setting state offices on fire included photo evidence. Those captured in the photos would face charges of arson, obstructing officials and destroying state property.
The case reports were submitted to the Department of Special Investigation and arrest warrants for arson were issued for three men captured in the photos, while arrest warrants were issued for four other suspects for supporting the arson attack.