However the impasse plays out, it is widely believed here that after the failure of both soft and hard approaches, Prime Minister Abhisit Vejjajiva will not last much longer in office.
He took office in December 2008 via a tenuous coalition of antagonistic parties created through parliamentary maneuvering rather than through a popular vote. Without a strong base of his own, he is a weak link in a government that is now under severe strain.
But even if he steps aside and elections are held, Thailand’s crisis is bound to continue, the product of a tectonic shift in which the country’s poor majority has begun to stir and to challenge an entrenched hierarchy of power that has dominated over the years.
The fugitive former prime minister, Thaksin Shinawatra, was the catalyst for that change, wooing the poor during his six years in power with populist programs like cheap medical care, loans and other financial breaks.
These are the so-called Red Shirts, mostly country folk, who have been camping in the capital for a month. They are devoted to Mr. Thaksin but also increasingly asserting their newfound rights as individual voters and as the country’s strongest electoral bloc.
Pushing back against them are the traditional elite and middle class, which coalesce around the monarchy and include established business interests and the military brass.
It is this sector that supported the military coup in September 2006 that ousted Mr. Thaksin. As the Yellow Shirts, they sought to bring down pro-Thaksin governments that took office when the military returned power to civilian hands a little more than a year later.
It was the Yellow Shirts who barricaded the prime minister’s office for three months in 2008 and closed Bangkok’s airports for a week at the end of that year.
If a new election is held, as the Red Shirts demand, and if it produces another pro-Thaksin government, as many analysts predict, the struggle is likely to continue.
Though the Red Shirts are on the march now, there were signs over the weekend of public opposition to them.
During Saturday’s clashes, bystanders sometimes cheered on the military, offered refreshments or gave them refuge to change out of their uniforms and flee the protesters.
On Sunday, one hospital reported that it was overwhelmed by people offering to donate blood to help wounded soldiers.
With both the military and the Red Shirts bloodied and angry, it was not clear what moves would come next, but it was the protesters who sounded the most assertive tone.
“There is no more negotiation,” said Jatuporn Prompan, a leader of the protesters, rejecting a government overture. “Although the road is rough and full of obstacles, it’s our duty to honor the dead by bringing democracy to this country.”
Speaking on television, the chief government spokesman, Panitan Wattanayagorn, said that troops were withdrawing to their barracks and that the government would seek a bipartisan investigation into the violence. “We are committed to make sure that justice is being done,” he said.
He asserted that soldiers had used mostly rubber bullets and had fired live rounds only into the air or in self-defense.
The political tensions have shaken Thailand’s peaceful and democratic image and cut deeply into its huge tourism industry, with 43 nations issuing travel warnings. Among the most recent was China, which canceled 100 charter flights carrying 15,000 tourists for this week’s water festival.
Bangkok has canceled traditional festivities on the well-known backpacker haven, Khaosan Road, which was the scene of bloody battles on Saturday night. On Sunday, tourists and Thais both wandered nearby, inspecting bullet holes, shell casings, blood stains and other evidence of the violence.
Not far away, people clambered over abandoned armored vehicles, using wrenches to pull off their treads and remove their heavy weapons until they were reduced to junk. “This land belongs to the people,” read a message painted on one vehicle.
Protest leaders said they planned to parade through Bangkok on Monday, carrying the bodies of some of the dead.
They said they had removed at least two of them from a hospital to preserve evidence of their deaths. Hospital officials confirmed that unknown people had come in and taken bodies away.