BANGKOK, Sept. 3 (AFP) - A Thai court ruled Thursday that two prominent activists should be jailed for breaching bail conditions by repeatedly joining youth-led anti-government protests calling for reforms to the kingdom's monarchy.

Anon Numpa and Panupong Jadnok had continued to speak out about the controversial issue since being arrested last month, and on Thursday Bangkok's Criminal Court revoked their bail, their lawyer said.

"They will be detained at Bangkok Remand Prison," lawyer Krisadang Nootjaras told reporters outside the court.

Human rights lawyer Anon was the first activist to air the long-taboo subject of monarchical reform during a protest last month. He was arrested days later along with Panupong.

They were the first people authorities charged with sedition following a massive July 18 demonstration, which kicked off a pro-democracy movement that has gathered steam across the country.

So far more than two dozen activists have been arrested, charged, and released on bail for involvement in protests that have drawn up to 20,000 demonstrators.

The pro-democracy movement is calling for the resignation of Premier Prayut Chan-O-Cha and a complete overhaul of his military-aligned government, which they consider illegitimate.

Protesters have also demanded reforms to the monarchy, demanded transparency to the royal family's fortune, and the abolition of royal defamation laws shielding the super-rich King Maha Vajiralongkorn from criticism.