Thailand’s government has announced an emergency decree to combat protests in Bangkok.
A televised announcement read out by police said “many groups of people have invited, incited and carried out unlawful public gatherings in Bangkok”.
“It is extremely necessary to introduce an urgent measure to end this situation”, it said.
Protesters have called for curbs on the king’s powers and for the resignation of Prime Minister Prayuth Chan-ocha.
They have set up camp near the prime minister’s office and confronted a motorcade carrying King Maha Vajiralongkorn on Wednesday.
The protesters, who were pushed back by ranks of police, raised the three-finger salute that has become a symbol of the protest movement.
The announcement on state television said protesters had “instigated chaos and public unrest”, and said emergency measures were needed to “maintain peace and order”.
The measures came into effect at 04:00 hours local time on Thursday (21:00 GMT on Wednesday).
The growing student-led protest movement, which began in July, has become the greatest challenge in years to Thailand’s ruling establishment. Protests over the weekend in the capital were some of the largest in years, with thousands defying authorities to gather and demand change.
Authorities say 18,000 people joined Saturday’s demonstration, although others gave higher figures. Many stayed to continue the protest into Sunday before dispersing.
The protesters’ calls for royal reform are particularly sensitive in Thailand, where criticism of the monarchy is punishable by long prison sentences.
Why are there protests?
Thailand has a long history of political unrest and protest, but a new wave began in February after a court ordered a fledgling pro-democracy opposition party to dissolve.
The Future Forward Party (FFP) had proved particularly popular with young, first-time voters and garnered the third-largest share of parliamentary seats in the March 2019 election, which was won by the incumbent military leadership.
Protests were re-energised in June when prominent pro-democracy activist Wanchalearm Satsaksit went missing in Cambodia, where he had been in exile since the 2014 military coup.
His whereabouts remain unknown and protesters accuse the Thai state of orchestrating his kidnapping – something the police and government have denied. Since July there have been regular student-led street protests.
Demonstrators have demanded that the government headed by Prime Minister Prayuth, a former army chief who seized power in the coup, be dissolved; that the constitution be rewritten; that the authorities stop harassing critics.