Security forces on both sides of the eastern border remain on high alert for supporters of Sam Rainsy, despite the Cambodian opposition leader being barred from boarding a flight to Bangkok for his promised return to challenge strongman Prime Minister Hun Sen.
Pol Col Ruangsak Buadaeng, the Klong Luek police chief, said on Friday that hotels were being checked to ensure Cambodian politicians were not staying in the area.
Roadside checkpoints were still in place in all districts in the easternmost province of Sa Kaeo, monitoring the movement of people towards the border. Posters of 21 Cambodian opposition politicians, including Sam Rainsy, were displayed with captions in both Thai and Khmer.
The posters feature a message issued by Banteay Meanchey police in Cambodia, asking people to call them immediately if they spot any of the "rebels".
In Poi Pet, villagers were banned from taking photos of soldiers ordered to patrol the Cambodian border town, raising tensions even further.
Cambodian authorities have asked Thai officials to keep an eye out for political rivals of premier Hun Sen, who are reportedly planning to return for protests against the strongman leader today, to mark Cambodia's Independence Day.
Cambodia gained independence from France on Nov 9, 1953.
Thai security forces in Surin, which also borders Cambodia, tightened security at the Chong Chom-Osmach border checkpoint but reported no unusual developments in the province.
Thai gamblers continued to flow across the border to visit Cambodian casinos all day yesterday, but the travellers and their vehicles had to submit to rigorous checks amid concerns over attempts to stir up political turmoil.
Armed Cambodian border guards have been told to brace for the unexpected, though there are no reports that Sam Rainsy and his group plan to slip into Cambodia through Surin.
But fear of possible violence prompted many Cambodian border vendors to stay put in Thailand until they feel it is safe to return home.
Sam Rainsy was barred from boarding Thai Airways International flight TG931 from Paris to Bangkok on Thursday. The airline said his ticket was not valid.
Prime Minister Prayut Chan-o-cha said this week he would not let the opposition leader pass through Thailand for his planned return to Cambodia.
In Phnom Penh, the United States yesterday expressed concern over Hun Sen's crackdown against democratic norms, which has seen the main opposition party disbanded, dozens of activists arrested and opposition leaders abroad preventing from returning.
Rights group Amnesty International meanwhile decried the cooperation offered by Malaysia and Thailand in preventing Cambodian opposition figures from returning home to rally support.
On Wednesday, Malaysia detained Sam Rainsy's US-based deputy, Mu Sochua, at Kuala Lumpur airport, before releasing her 24 hours later along with two fellow opposition leaders detained earlier. Mu Sochua remained in Kuala Lumpur and said she still plans to return to Cambodia by land.