Anti-government protesters poured bottles of their own blood outside the Thai prime minister's office today, a "sacrifice for democracy" after demands for elections were rejected.
Hoping to re-energise a movement waning after four days of peaceful protests, supporters of ousted premier Thaksin Shinawatra gathered at a heavily guarded Government House to splash 300 litres of their blood at the gates.
The government showed no sign of heeding pressure to call polls, which Mr Thaksin's allies would be well placed to win.
The absence of violence and a growing view that Prime Minister Abhisit Vejjajiva, with the backing of the military, can ride out the crisis was a key factor helping lift Thailand's stock market 2.4 per cent to a two-month high today.
At the rally site, some "red shirts" dwelled on their failure to achieve their goal as others withered under Bangkok's scorching sun. Of the 150,000 demonstrators who had massed on Sunday night, many had left. Police say about 30,000 remained.
"We will continue. The people will decide how long we will stay," Weng Tojirakarn, a protest leader, said.
"This is certainly a success. We have put concepts of class difference and double standard in the public mind."
Throughout the day, "red shirts" lined up under a tent to give 10 cubic cm (0.6 cubic inches) of blood to medical volunteers and nurses, which was paraded on stage in 5-litre bottles after their symbolic shedding of blood.
About 2,000 soldiers and police guarded Mr Abhisit's office as protesters watched a priest in white perform a ritual to curse the premier.
Despite days of fiery rhetoric by demonstrators on how the mainly rural "red shirts" have been marginalised by the military, urban elite and royalists who back Mr Abhisit, some expressed frustration about the rally's lack of impact.
Fears of violence briefly surfaced yesterday when three grenades exploded at a Bangkok army base, wounding two soldiers. It was unclear whether the attack was linked to the rally. Waning numbers could also push some frustrated protesters to step up the fight, risking a confrontation with authorities.
The twice-elected Thaksin was ousted in a military coup in 2006 and later sentenced in absentia to two years jail for graft. He fled into exile shortly before his sentence was passed and lives mainly in Dubai, although thought now to be in Europe.
Core "red shirt" leaders echoed Mr Thaksin's recent calls for patience but analysts said a drop in numbers may force the leaders to start looking for ways to end the rally for now.
Asked if he was ready to talk to the protesters, Mr Abhisit told reporters at a military base where he has been using as a command centre: "If they want to exchange ideas ... I am willing to listen, but I have to decide on the basis of the whole country."
His deputy, Suthep Thaugsuban, said the government remained vigilant with continued intelligence about security threat. Critics have accused the government of fearmongering.
Reuters