A rights group says three Thai citizens who were accused of insulting the king have disappeared.
Thai Alliance for Human Rights claims there’s no sign of the trio after they were arrested in Vietnam.
However Prawit Wongsuwan, Thailand’s deputy prime minister, denies the activists were in Thai custody.
The incident comes months after two exiled critics of the monarchy were found dead.
Last week Thailand crowned its new king, Maha Vajiralongkorn, in an elaborate ceremony at the Grand Palace in Bangkok.

Afghanistan says Pakistan strikes kill and injure dozens
Police officer killed, dozens injured in bomb explosions in Ukraine's Lviv
Trump pivots to new 15% global tariff after Supreme Court setback
Hong Kong plans to buy homes devastated in deadly high-rise fire
US Supreme Court strikes down Trump's global tariffs
