Around 20,000 Red Shirt protesters rallied in Bangkok Sunday to mark the third anniversary of a bloody crackdown on anti-government protests which exposed Thailand's deep divisions, police said.
About 90 people were killed and nearly 1,900 wounded in a series of street clashes in May 2010 between demonstrators and security forces, which culminated in the military crackdown.
On Sunday roads were blocked as Red Shirts, loyal to ousted self-exiled former leader Thaksin Shinawatra, massed at an intersection in Bangkok's glitzy shopping district.
Central World, Thailand's largest shopping mall which was torched in the final days of the 2010 protest, was also closed while the colourful rally took place.
Thai special branch estimated that 20,000 people had joined the gathering by early evening.
"The protest is peaceful," said Police Major General Chantavit Ramasut earlier, adding that around 750 policemen were keeping watch.
Thailand has been racked by sometimes explosive political divisions since Thaksin was ousted by the army in a 2006 coup.
Rights groups have called for the perpetrators of the 2010 violence to be prosecuted. They condemn moves by the current government of Yingluck Shinawatra, Thaksin's sister, to push through an amnesty for the political violence.
Analysts say an amnesty would both appease the royalist army and pave the way for Thaksin's bid to return to the kingdom.
"Three years ago, the world saw soldiers shooting protesters and parts of Bangkok going up in flames," said Brad Adams, Asia director at Human Rights Watch.
"But instead of investigating and prosecuting those responsible, successive Thai governments and the army have politicised efforts for justice and are now backing an amnesty bill that would let everyone off the hook."
The crackdown followed weeks of rallies by the Red Shirts which brought parts of central Bangkok to a standstill.
Then-prime minister Abhisit Vejjajiva, who oversaw the military crackdown, has blamed protest leaders for the violent denouement and said his government had no choice but to take tough action.
Courts have ruled that some protesters were killed by security forces, leading to charges of murder being laid against Abhisit -- accusations he strenuously denies.
A trial of 24 Red Shirt leaders on terrorism charges began in December but five of them enjoy immunity as they are now lawmakers, so the case is expected to take years to complete during breaks in the parliamentary session.
The Red Shirts were demanding immediate elections, accusing Abhisit's government of coming to power unfairly in 2008 through a parliamentary vote after a court stripped Thaksin's allies of power.
On Sunday the memory of the dead was still raw.
"I come every year and I have to come every year, I miss the people who sacrificed themselves, I will come until there is real democracy," said Thanadej Nonprocha, 45, from the Red Shirt heartland of northeastern Thailand.