Protesters declared their intention to stay camped outside Government House for at least three days to put pressure on Prime Minister Prayut Chan-o-cha to step down.
Aside from ousting the former coup leader from the premier's post, "Khana Ratsadorn” (the People's Group), -- formerly known as the Free People movement -- are also demanding that the constitution be rewritten and the monarchy reformed.
"We have reached our destination," leader Arnon Nampha declared after the demonstrators -- whose numbers appeared to be in the tens of thousands, although one of their leaders claimed 300,000 -- arrived at the prime minister's office, about four hours after starting their march from the Democracy Monument at 2.40pm.
Protest leaders said they will rally outside Government House for at least three days in their bid to force Prayut to resign.
The rally has largely been peaceful so far, with only minor confrontations with police and a few of the yellow-shirted pro-monarchists, who according to some reports were brought in by authorities.
The royalists lined up along Ratchadamneon Avenue to show their support for His Majesty the King as his royal motorcade moved from Dusit Palace to the Grand Palace for a religious function.
Suwit Thongprasert, formerly known as Phra Buddha Isara, announced that the yellow-shirted group would disperse after the King returned to the palace.
The prime minister was in Pathum Thani to chair activities initiated by His Majesty, and his office will be closed on Thursday.
