The United Front for Democracy against Dictatorship (UDD) on Tuesday marked the tenth anniversary of the 2010 political clashes with a vow to never let the red-shirt movement die.
One memorial event was broadcast on the Facebook account of UDD News -- a red-shirt news outlet, attended by leading red-shirt figures who included Tida Tawornseth, Nattawut Saikuar, Weng Tojirakarn, Veerakarn Musikkapong and Korkaew Pikulthong.
Mr Korkaew said the red shirts came together to mark the anniversary of one of the "cruellest events" in Thai political history, in which 94 people -- mostly red-shirt supporters -- were killed.
People from a new generation are beginning to stand alongside the red shirts who lived through those events to call for justice, he said.
"Over the past 10 years, efforts have been made to destroy democracy advocates either by bullets or by rhetoric. This has only drawn more people to the red shirts because they know that we fight for a universal cause," Mr Korkaew said.
"This is proof that the red shirts will never die. Democracy may be slow to take root in Thailand, but it surely will some day," he said.
Mr Veerakarn said the dispersal of red-shirt protesters in 2010 has made people more politically conscious and mature.
Speaking at another merit-making ceremony at a Bangkok temple to remember those killed in the unrest, UDD chairman Jatuporn Prompan said red shirts have had to keep a low profile since those events.
Instead of receiving justice they had to fight charges stemming from the protests, he said.
He dismissed allegations that the UDD was involved in burning buildings during the crackdown on protesters.
Terrorism charges were laid against 24 UDD leaders which were subsequently dismissed by Criminal Court on Aug 14 last year. Despite dismissal of the terrorism charges, some red-shirt leaders still face penalties for derailing the Asean summit in 2009.
The red shirts then resorted to street demonstrations which lasted 70 days from February to May 2010.
They claimed the Abhisit Vejjajiva government had no legitimacy because the army was behind its rise to power following the "politically motivated" dissolution of the People's Power Party of former premier Thaksin Shinawatra.
The UDD claimed the peaceful protest turned bloody when security forces attacked demonstrators following failed negotiations.
Apart from the red shirts, seven soldiers and two foreign reporters were also killed in the violence.