Thousands of anti-government protesters gathered in Bangkok on Sunday for the latest in a series of rallies calling for the release of their key leaders in prison on terrorism charges.
An estimated 15,000 "Red Shirts" -- the movement behind mass protests in the capital last year -- gathered near Democracy Monument amid a heavy security presence, national police spokesman Prawut Thavornsiri said.
"The situation is normal," he said, adding that 5,000 police were deployed for the event, which fugitive former premier Thaksin Shinawatra was expected to address in the evening from overseas.
Thaksin remains a controversial figure in Thailand who draws support among the mainly poor and working class Red Shirts but is loathed by the urban elite, who see him as corrupt, authoritarian and a threat to the revered monarchy.
Earlier in the day red-clad protesters laid red roses in front of Bangkok's Criminal Court where a letter from detained leaders was read out.
Mass protests in April and May of last year by the Red Shirts left 90 people dead in a series of street clashes between demonstrators and the army, which broke up the demonstration.
The Reds, who were campaigning for immediate elections, have held a series of peaceful one-day rallies in the capital in recent weeks.
Rival "Yellow Shirt" nationalist activists meanwhile have been rallying recently near Government House calling for Prime Minister Abhisit Vejjajiva to step down over his handling of a deadly border dispute with Cambodia.
The "Yellow Shirts" were once allies of the establishment-backed Abhisit, but relations have soured.
Abhisit said last week he would call a general election in the first half of this year if there was no fresh political violence.
The government recently invoked the Internal Security Act in Bangkok to cope with the renewed political rallies.