Riot police began pulling back from the road at 11.30am. They announced that their attempt to clear the site was a symbolic gesture that officials intend to reclaim Chaeng Watthana government complex from protesters, a Bangkok Post reporter at the scene said.
People's Democratic Reform Committee (PDRC) protesters blew whistles as the police retreated.
Officers assembled in nearby Laksi at around 8am before attempting to retake the rally site, prompting Luang Pu Buddha Issara and rally organisers to call on people to block the efforts of the authorities.
Police had advanced to within 50 metres of protesters before withdrawing to at least 200 metres apart.
Around 1,000 police deployed in the area were from the Provincial Police Region 1, the Pacific news centre reported.
Chaeng Watthana is one of four PDRC rally sites. The anti-government group's other rally stages are at Pathumwan, Lumpini, Ratchaprasong and Asok intersections.