The anti-government demonstrations demanding the resignation of Prime Minister Prayuth Chan-ocha continued through the night, and by early morning authorities had issued an emergency decree banning gatherings of more than four people.
Thai police have arrested more than 20 people under sweeping new emergency measures, with pro-democracy activists reporting a handful of high-profile leaders are among those detained.
The arrests came after thousands gathered in Bangkok, including on the route of a royal motorcade, with many raising a defiant three-fingers.
The salute, borrowed from the "Hunger Games" books and films, has been harnessed by the youth-led movement as a symbol calling for democratic change.
"More than 20 people were arrested," deputy police spokesman Kissana Phathanacharoen said.
Kissana added that student leaders issuing calls to gather for a fresh protest on Thursday "are committing wrongdoings."
Moments before her own arrest was livestreamed, prominent student leader Panusaya Sithijirawattanakul said human rights lawyer Anon Numpa and student leader Parit Chiwarak, better known as "Penguin", were among those detained.
While protest leaders called for renewed protest at Ratchaprasong Intersection at 4pm today after dispersing, some including Thammasat University student leader Rung has been arrested at a hotel this morning. #WhatHappensinThailand #Thailand #ม๊อบ14ตุลา #คณะราษฎร2563 #รุ้งปนัสยา— Pravit Rojanaphruk (@PravitR) October 15, 2020
Thai police have dispersed protesters who camped out overnight outside the office of the prime minister.
Earlier on Thursday, Thailand's government ordered a ban on gatherings of five or more people and the publication of news or online messages that could harm national security under an emergency decree to end Bangkok street protests.
Protests have been escalating for three months and protesters set up camp outside Prime Minister Prayuth Chan-ocha's offices to demand his resignation late on Wednesday. The government said it also acted after demonstrators obstructed a royal motorcade.
"It is extremely necessary to introduce an urgent measure to end this situation effectively and promptly to maintain peace and order," state television announced.
It was accompanied by a document setting out measures that took effect from 4am local time (2100 GMT) to ban big gatherings and allowing authorities to ban people from entering any area they designation.
It also prohibits: "publication of news, other media, and electronic information that contains messages that could create fear or intentionally distort information, creating misunderstanding that will affect national security or peace and order."
An Associated Press journalist later saw riot police advance from multiple locations to force out a few hundred protesters who remained outside Government House, the seat of Minister Prayuth Chan-ocha. Protesters were seen taken away into police trucks.
Local media reported that the police operation came after Prayuth declared a severe state of emergency in the Bangkok area to allow authorities to move against the protests.
Thailand is technically still under a state of emergency as part of coronavirus restrictions.
Before the police dispersal, a large number of protesters had already left the area after one of their leaders announced the end of the rally at Government House though a few hundred stayed on. It was also announced that the rally would move to a different location in the capital Thursday afternoon.
The latest rally started on Wednesday with thousands of protesters marching from Bangkok’s Democracy Monument to Government House. It was the third major gathering by activists who want to keep up the momentum in their campaign for democratic change.
The protesters have drawn attention because of their demands for reforms to Thailand’s constitutional monarchy, which they claim does not properly operate in a democratic framework.
That demand has caused a huge controversy because the royal institution has long been considered sacrosanct and a pillar of Thai identity. It is also protected by a lese majeste law that mandates three to 15 years in prison for defaming the monarchy.
Conservative royalist Thais accuse them of seeking to end the monarchy, an allegation they deny. Before leaving Democracy Monument, several small clashes broke out between protesters and their opponents, who traded punches and threw plastic bottles as police tried to keep them apart.
The protest movement was launched in March by university students but quickly put on hold as Thailand was gripped by surges in coronavirus cases. It came back in July, when the threat from the virus eased, and since then has again been spearheaded by students and publicized on social media.
The movement’s original core demands were new elections, changes in the constitution to make it more democratic, and an end to intimidation of activists.
The protesters charge that Prayuth, who as army commander led a 2014 coup that toppled an elected government, was returned to power unfairly in last year’s general election because laws had been changed to favour a pro-military party. Protesters say a constitution promulgated under military rule is undemocratic.