Police forced a rights group to cancel the launch of a report alleging Vietnam's persecution of an ethnic minority on Friday, saying it could harm relations between the Southeast Asian neighbours.
The launch of the 33-page report by the New-York based Human Rights Watch outlining Vietnam's persecution of ethnic Montagnard Christians in the central highlands was due to take place at the Foreign Correspondents' Club of Thailand in Bangkok.
But undercover soldiers and police turned up at club to shut down the event, a FCCT official told Reuters, declining to be named.
Police said they acted pre-emptively after receiving a request from the Vietnamese government.
"Vietnamese officials had sent a request to the Royal Thai Police to pay attention to the event," Pol Col Pornchai Chalordet, superintendent of the Lumpini police station in Bangkok, told Reuters.
Pol Col Pornchai said the event was deemed potentially damaging to foreign relations.
Pol Col Kittiporn Boongsong, who was at the scene, told Reuters police had only asked for "cooperation". He said that the junta did not order the event's cancellation.
Human Rights Watch in a statement said it was disappointed.
"This action today is just the latest indication that Thailand is choosing to side with dictatorships in Asia," it said.
This was the third event to be cancelled at the request of Thai authorities within two months, the FCCT official said.
In 2010 Thailand, under pressure from Vietnam, denied visas to two political activists seeking to speak at an FCCT event.