On Sunday, Thai police fired a burst of water cannons at thousands of pro-democracy protesters marching to Bangkok's Grand Palace to demand restrictions on the powers of King Maha Vajiralongkorn and the removal of the government, Reuters reported.
During the brief confrontation outside the palace, where police had set up a barricade of buses and barbed wire to stop demonstrators from proceeding, the Bangkok Authority's emergency unit said one police officer and four protesters were hurt.
During the months-long protests, officers used the cannon for only the second time to demand the departure of Prime Minister Prayuth Chan-Ocha, a former junta leader who seized power in a 2014 coup. Police spokesman Kissana Phathanacharoen said the water cannon was fired "only as a warning" on Sunday.
Protesters said in a declaration addressed to King Maha Vajiralongkorn that he should listen to "fearless critiques," as well as flattery and praise. "When you hear all the people's flattering praise, you must also hear fearless criticisms and suggestions all the same," the declaration said, signed by "people" with "power of equal human dignity."
According to the BBC, Thailand's lèse-majesté law prohibits insulting the monarchy and is among the strictest in the world.
More than 10,000 protestors marched from the Democracy Monument in central Bangkok, Reuters estimated. But the number was put by the police at 7,000. According to The Guardian, demonstrators, who wore goggles and hard hats for protection, moved buses and removed the barbed wire that the police had used to block access to the palace. They carried mock letterboxes made of old rubbish bins that were addressed to the Royal Household Bureau to deliver letters urging reforms by hand.
In the meantime, several dozen royalists had held a counter-protest at the Democracy Monument earlier, wearing the king's yellow shirts and waving Thai flags. Pictures of the king and his late father, King Bhumibol Adulyadej, were held up by many.
The government of Thailand arrested many prominent protest leaders last month and announced a ban on gatherings of more than five individuals using an emergency decree. Since July, protests have been going on.
The demands of the protesters include repealing laws against defaming the monarchy, a new constitution, abolishing royal offices, ousting the government led by the military, and disbanding the royal guards of the king. The protestors also called for an end to the intimidation of critics of the government.