Thai activist 'first to be arrested for royal insult' under 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

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.

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.