An anti-government protest in Thailand drew more than 10,000 people on Sunday, the largest political demonstration the kingdom has seen in years as a pro-democracy movement gathers steam.
Student-led groups have held near-daily protests across the country for the past month to denounce Premier Prayut Chan-O-Cha -- a former army chief who led a 2014 coup -- and his military-aligned administration.
By Sunday evening the protesters -- who are demanding major democratic reforms -- had taken over the busy intersection around Bangkok's Democracy Monument, which was built to mark the 1932 revolution that ended royal absolutism.
Police closed off surrounding main roads to stop incoming traffic, and an official at Bangkok's Metropolitan Police Bureau told AFP the crowd size had grown to 10,000 by 6:00 pm (1100 GMT).
"Down with the dictatorship," the students chanted, many holding signs critical of the administration. Others held bird-shaped cutouts representing peace.
The peaceful gathering at Democracy Monument is the largest the kingdom has seen since Prayut staged a putsch in 2014.
Partly inspired by the Hong Kong democracy movement, the protesters claim to be leaderless and have relied mostly on social media campaigns to draw support across the country.
"Give a deadline to dictatorship" was the top Twitter hashtag in Thailand on Sunday.
They are demanding an overhaul of the government and a rewriting of the 2017 military-scripted constitution, which they believe skewed last year's election in favour of Prayut's military-aligned party.
Organiser Tattep Ruangprapaikitseree reaffirmed the call Sunday, adding that the government must "stop threatening the people".
"If there's no positive response from the government by September, we will step up," Tattep shouted to a sea of supporters holding up their mobile phones as flashlights.
Tensions have risen over the last two weeks with authorities arresting three activists. They were released on bail after being charged with sedition.
They were told not to repeat the alleged offences, but two of them -- prominent student leader Parit Chiwarak and human rights lawyer Anon Numpa -- arrived at the protest venue on Sunday flanked by cheering supporters.
A rally last week by around 4,000 demonstrators called for the abolition of a law protecting Thailand's unassailable monarchy, and for a frank discussion about its role in Thailand.
King Maha Vajiralongkorn sits at the apex of Thai power, flanked by the military and the country's billionaire business elite.
A draconian "112" law can see those convicted sentenced to up to 15 years in jail per charge.
During Sunday's demonstration, which drew a diverse crowd of all ages, many said they agreed with the student demands.
"We can't let the students walk on this difficult path alone," a 68-year-old woman told AFP, declining to provide her name.
- Growing discontent -
But the increasingly bold pro-democracy movement also has its detractors.
Standing at one corner of the monument's intersection were dozens of royalist protesters carrying portraits of the king and queen, shouting "Long live the king".
Prayut last week described the protesters' demands as "unacceptable" for Thailand's majority, calling the pro-democracy movement "risky" a day before Parit was arrested.
Sunday's massive turnout is meant to send a message to the government that "they cannot forever use legal mechanisms against the people", said political analyst Titipol Phakdeewanich of Ubon Ratchathani University.
"They can see that it's only used to serve the interests of the military and the establishment parties."
After the eight-hour rally, the activists linked arms and marched to a nearby police station to challenge authorities on arrest warrants that local media reported were issued for various leaders.
The police did not arrest anyone, and after a brief stand-off, the activists left.
Thailand has long seen a cycle of violent protests and coups, with the arch-royalist army staging more than a dozen putsches since 1932.
The growing discontent also comes as the kingdom goes through one of its worst economic periods since 1997 because of the coronavirus pandemic.
Millions have been left jobless, and the crisis has exposed the inequalities in the Thai economy, which is perceived to benefit the elite, pro-military establishment.