Thailand's government has ordered police to stop confronting protesters demanding the resignation of the prime minister.

The move raised hope that days of political violence may end, but the leader of the campaign said the fight would go on.

The protesters opposing Prime Minister Yingluck Shinawatra had been besieging various government buildings, including Government House, the complex that houses her offices.

After days of firing tear gas and rubber bullets to hold them off, police handed out roses to flag-waving protesters after the barricades were brought down.

The protesters mingled with police, shouted slogans and left peacefully.

"The current political situation of our country has yet to return to normal, although it has begun to ease up," Ms Yingluck said in a short televised statement, again stressing she wanted the security forces to avoid confrontation and loss of life.

The protests were the latest eruption of conflict between the Bangkok-based establishment and forces loyal to Ms Yingluck and her brother, former premier Thaksin Shinawatra.

Five people have been killed in clashes since the weekend and scores hurt.

Protest leader Suthep Thaugsuban said the campaign against what he called the "Thaksin regime" would continue.

Hundreds of demonstrators still occupy the Finance Ministry and a state administrative centre, but it remains unclear if Mr Suthep will be able to motivate his people again.

Police estimated that only 9,400 were still on the streets, including 5,500 at Democracy Monument, a roundabout in the old city that has been their base.

Thursday is the birthday of much-revered King Bhumibol Adulyadej and the protests are unlikely to continue on what is traditionally a day of prayer and celebration.

"It's a ceasefire, they don't want to crush each other just before the king's birthday. This is out of respect," said Nakarin Mektrairat, a political analyst at Bangkok's Thammasat University.

"The next step is negotiations, but what will be negotiated, nobody knows."

The government said it wanted to avoid more violence and ease the tension for the king's birthday.

"The government is still doing its job. This morning we had a cabinet meeting as usual," Deputy Prime Minister Pongthep Thepkanchana said.

"We haven't given up, but today the police have backed off because we see the protesters just want to seize these places as a symbolic action, so we want to compromise."

Ms Yingluck said she wanted to open talks with the protesters, academics and business people to discuss political reform and find a democratic solution.

The demonstrators celebrated what they called a partial victory even though the government they hate remains in place.

"We will fight on until the Thaksin regime has been driven out," Mr Suthep told his supporters.

Mr Suthep had vilified the police in a speech on Monday and said the protesters would capture their city headquarters.

City police chief Kamronvit Thoopkrachang said his men would not resist.

Mr Kamronvit is close to Mr Thaksin, himself a former policeman and then a telecommunications tycoon, who became Thailand's most popular politician with measures to help the urban and rural poor.

Mr Suthep is a former deputy prime minister of a government bitterly opposed to Mr Thaksin that ordered the military to put down pro-Thaksin protests in 2010. About 90 people were killed.

Ms Yingluck's government came to power with a landslide election victory in 2011.

Mr Thaksin was ousted by the military in a 2006 coup, but army chief Prayuth Chan-ocha told reporters the army was not getting involved this time: "This is a political problem that needs to be solved by political means. However, we are monitoring from a distance."