PHNOM PENH/BANGKOK (Reuters) – Unknown gunmen abducted a Thai political activist in Cambodia, rights advocates said on Friday, in the latest in a series of mysterious disappearances of Southeast Asian dissidents living in exile.

Wanchalearm Satsaksit, 37, was kidnapped at gunpoint and bundled into a vehicle as he walked on a street in front of his apartment in the capital, Phnom Penh, on Thursday, New York-based Human Rights Watch said.

“The abduction of a prominent Thai political activist on the streets of Phnom Penh demands an immediate response from Cambodian authorities,” said Brad Adams, the group’s Asia director.

A Cambodian police spokesman told Reuters authorities had not detained or arrested the activist and there was not enough information for police to open an investigation.

Wanchalearm fled from Thailand after a 2014 military coup. He had been summoned by military authorities before he left.

He kept up his politically activity in exile and Thai authorities issued an arrest warrant for him in 2018 for violating a Computer Crime Act by operating a Facebook page critical of the military government.

Just on Wednesday, he criticised Thai Prime Minister Prayuth Chan-ocha on social media.

According to a 2015 Thai media report citing a security source, Wanchalearm was among 29 exiled activists accused of violating a lese majeste law that makes it a crime to defame, insult or threaten the monarchy.

At least eight Thai activists who fled after the 2014 coup and took refuge in Laos, Cambodia and Vietnam have disappeared (here), associates and rights groups say, with some found dead.

The hashtag #SaveWanchalearm was trending on Thai Twitter on Friday with more than 400,000 re-tweets and some activists planned a demonstration later in the day.

Human rights groups have accused governments in Southeast Asia, including Cambodia, Thailand and Vietnam, of helping each other to forcibly return (here) several dissidents and asylum seekers in recent years.