About 3000 to 4000 protesters chanted "Long live democracy" at Thammasat University on the outskirts of Bangkok on Monday night, with speeches calling for the resignation of Prayuth, who first took power in a 2014 coup, and an end to military domination of politics.

But protesters from a Thammasat University Pro-democracy Group also issued a 10-point call for reform of the monarchy, becoming at least the third student protest group to break a decades-long taboo on questioning its role and powers.

Thailand has strict laws against insulting or defaming the king, punishable by up to 15 years in prison.

Palace officials declined to comment on the student protests or on any criticism of the monarchy.

Former army chief Prayuth told reporters he had watched the protests.

"Yes, I watched it, how can I not?" he said when asked about the students' demands.

"I am concerned," he said, but did not elaborate on what concerned him and did not comment on the demands for royal reform.

Prayuth has warned protesters against involving the monarchy in their protests but said King Maha Vajiralongkorn, who took the throne after the death of his father in 2016, has asked him not to arrest anyone under the "lese majeste" laws.

Since the 2014 coup, activists have accused Prayuth of using the military's close association with the palace to justify its grip on power, including accusations of manipulating results of elections last year. Prayuth denies the allegations.

The students' new demands included reversal of a 2019 order that transferred two army units to the king's personal command and a 2017 law that gave him full control of the crown's extensive property holdings.

Australian Associated Press