About 30,000 Thai "Red Shirts" gathered in Bangkok on Sunday, police said, in their biggest show of strength since a deadly military crackdown on their mass anti-government protest last year. A security force of 1,000 was deployed in the capital for the march, at which members of the movement, dressed in their trademark red clothing, clapped and sang, some with banners backing non-violence.
Police Major General Piya Utayo of the Metropolitan Police told AFP that 30,000 people had gathered for the rally - a figure also confirmed by a special branch police source.
The Red Shirts have vowed to hold rallies twice a month in Bangkok to secure the release of their leaders who were jailed after their protest in April and May last year, which saw more than 90 people killed in clashes with troops.
"I'm doing my best to call for the release of people jailed and to remember those who lost their lives," said Jatuporn Prompan, a lawmaker and one of the senior Red Shirts facing terrorism charges.
Jatuporn, who himself has been granted bail, said legal experts had told him he could take part in the protest without violating his bail conditions so long as he did not speak to the crowds.
Thaksin Shinawatra, the Red Shirts' hero and former prime minister who was ousted by a military coup in 2006, was expected to make a phone-in to the rally. He now lives abroad to escape a jail term for corruption.
Many of the mainly poor and working class Red Shirts support the controversial ex-premier for the populist policies he implemented when in power, but he is hated by the urban elite.
Sunday's rally comes as Prime Minister Abhisit Vejjajiva - whose term runs out at the end of this year - announced a new welfare package, which is designed to help low-income groups and address social inequalities.
The Red Shirts' two-month rally last year, which attracted 100,000 people at its peak in support of their demand for immediate elections, was brought to a bloody end on May 19 with a military assault on the group's base.
After the crackdown, a small band of militant protesters set dozens of buildings ablaze across Bangkok, including a glitzy shopping mall.
The group has since staged several rallies in the capital, the last attracting around 10,000 on December 19, despite a state of emergency banning gatherings of more than five people, which was lifted late last month.
On Saturday a bomb in the Thai north-east, the Red Shirts' heartland, damaged a school named after the king's top aide but caused no injuries.
The bomb damaged the library at the school named after General Prem Tinsulanonda, the head of the king's privy council and a former prime minister whom the "Red Shirts" believe masterminded the coup that deposed Thaksin. An intelligence official said the attack seemed designed to cause political unrest.