BANGKOK (Reuters) - Thai police arrested an anti-junta activist on Saturday for defaming the monarchy in what rights groups said was the first case of lese-majeste brought under Thailand’s new king.

Thailand's new King Maha Vajiralongkorn Bodindradebayavarangkun is seen on his way out from the Grand Palace in Bangkok, Thailand, December 2, 2016. REUTERS/Jorge Silva

King Maha Vajiralongkorn formally ascended the throne on Thursday following the death of his father, revered King Bhumibol Adulyadej, who died aged of 88 in October.

Police Colonel Jaturon Trakulpan, a superintendent in northeastern Chaiyaphum province, said Jatupat Boonpattararaksa, an activist who has staged several anti-junta protests, was arrested and charged with royal insult under Article 112 of Thailand’s criminal code.

“We caught him at a temple,” Jaturon said.

Thailand’s junta has cracked down on critics of the monarchy since it took power in a May 2014 coup. iLaw, a Bangkok-based group that monitors such cases, said they had increased since King Bhumibol’s death.

Article 112 says anyone who “defames, insults or threatens the king, the queen, the heir-apparent or the regent” will be punished with up to 15 years in prison.

Thai Lawyers for Human Rights, a rights group representing Jatupat, said in a Twitter post that he was charged with royal insult for sharing a link on Facebook to a BBC Thai-language profile of the new king.

Anon Chawalawan of iLaw said the case was the first royal insult case to be filed under the new monarch.

“This post was shared many times. We question why he was singled out,” Anon told Reuters. “It might be because he has a history of staging anti-junta protests.”

International rights groups and some Bangkok-based Western diplomats have decried Thailand’s harsh sentences for lese-majeste convictions.

Last year, two people received record jail sentences of 25 and 30 years respectively for Facebook posts deemed insulting to the monarchy.