|The red shirts demand the release of their leaders who were detained in last year's protests [GALLO/GETTY]
About 30,000 supporters of Thailand's "red shirt" movement have gathered in the capital, Bangkok, demanding the release of the group's leaders who were detained in the wake of last year's deadly violence.
Sunday's anti-government protest appeared to be peaceful at large, but a brief scuffle occurred in the upmarket Ratchaprasongan shopping area where police had tried to seal off the main intersection with barricades.
A few hundred protesters hurled plastic water bottles and pushed past the police, who stepped aside to avoid further conflict.
More than 1,000 police were deployed across the city.
Jatuporn Prompan, a red shirt leader who avoided arrest because he has parliamentary immunity, vowed to hold "frequent and symbolic gatherings" twice a month - a change from the large sit-in last year that lasted 10 weeks and prompted a violent crackdown.
"We have learned a lesson that big gatherings will not lead to the result we want," Jatuporn said.
About 90 people were killed and more than 1,400 were wounded in the March-May unrest, as the protesters tried to force Abhisit Vejjajiva, the prime minister, to call early elections.
The rally comes as Abhisit has announced nine welfare policies, aimed at addressing social inequalities and helping low-income groups in the country.
Sunday's protest was the first major rally since Abhisit's government on December 22 lifted a state of emergency in Bangkok that technically barred gatherings of more than five people.
Al Jazeera's Wayne Hay, reporting from Bangkok, said protesters would march on two main locations: Democracy Monument and Ratchaprasong Intersection.
"These two areas were the scene of some of the worst violence during that long-running red shirt rally last year," he said.
"The lifting of the state of emergency basically means that, among other things, the military takes a step back from day-to-day security and hands over to the police."
Even though the state of emergency has been lifted, however, the army could still be redeployed.
"Bangkok remains under the Internal Security Act, and that means that if the security situation worsens, the troops can be redeployed," Hay said.
A day ebfore the rally, a bomb was reported to have exploded in the country's northeast, the heart of the opposition movement. No injuries were reported after the early morning explosion in Khom Kaen province.
The bomb damaged the library at a school named after General Prem Tinsulanonda, the head of the king's privy council and a former prime minister who the red shirts believe masterminded a coup that deposed former prime minister Thaksin Shinawatra in 2006.
A government intelligence official in Khon Kaen said the home-made bomb was likely a "symbolic" attack, as it destroyed a sign bearing the general's name.
"The preliminary assumption is that it was to incite political unrest," the official, who requested anonymity, told the AFP news agency.