BANGKOK (BLOOMBERG) - Thailand has threatened to take legal action over posts critical of the monarchy made on social media platforms as student-led protests calling for greater democracy and curbs to the power of King Maha Vajiralongkorn gather steam across the country.

Digital Economy Minister Buddhipongse Punnakanta ordered the authorities to identify "inappropriate" posts and singled out 114 posts mostly made on Facebook, but also Twitter and YouTube, that may be in breach of the Computer Crimes Act.

"All evidence will be gathered and submitted to court tomorrow," he wrote on Facebook late on Tuesday (Aug 11).

"Once the court has issued an order, it will be forwarded to the three platforms. If within 15 days, the accounts are not closed or posts deleted, we'll immediately take legal action."

Facebook, Twitter and Google didn't immediately respond to a request for comment.

According to the law, fines for violations are a maximum of 200,000 baht (S$8,840) and daily fine of no more than 5,000 baht per post, he wrote.

Thailand has strict lese-majeste laws criminalising insults against top members of the royal family, which have resulted in lengthy jail sentences.

The announcement comes after thousands of demonstrators gathered on Monday as part of near-daily gatherings which have gained momentum after the arrests of top leaders, who have since been released on bail.

They reiterated a rare public call last week by one of those arrested, Arnon Nampa, for rolling back measures that increased the power of King Vajiralongkorn since he took the throne in 2016.

Some groups have also demanded that the government rewrite the Constitution by the end of September to disband the military-appointed Senate and change election laws to make them more democratic, after which the government would resign and hold a new vote.