Anti-government protesters together with the general public were cleaning up roads and pavements at Ratchadamnoen rally site on Wednesday morning, in preparation for His Majesty the King's 86th birthday tomorrow, Dec 5.

Reports said Bangkok Governor Sukhumbhand Paribatra led dozens of water trucks and garbage trucks to help the public cleaning up the area, where protests against the Yingluck government have been continuous for almost a month.

Mops, brooms and cleaning solutions were donated by different sectors, as part of the '"Big Cleaning Day" campaign announced by anti-government leaders.

Another group of demonstrators also went to tidy up the Ministry of Interior, which they occupied last week in an act of civil disobedience against the government.

Protesters on Wednesday marched to Bangkok's national police headquarters, a day after a sudden truce in honour of the King's birthday ended a spate of increasingly fierce street fighting.

The pause in violence came suddenly Tuesday, when Prime Minister Yingluck Shinawatra ordered police to end their resistance against masked mobs who had begun attacking their positions beside her office compound with homemade rocket launchers and petrol bombs.

The move was timed to coincide with celebrations of the King's birthday, a holiday that holds deep significance in Thailand. It was widely seen as offering demonstrators a face-saving way out of a crisis that has killed four people and injured more than 256 since the weekend.

But protest leader Suthep Thaugsuban vowed to keep up his struggle to overthrow Ms Yingluck and keep her brother, fugutive former prime minister Thaksin Shinawatra, from returning to power.

"You can rest assured that this is a victory that is only partial ... because the tyrannical Thaksin government endures," Mr Suthep said.

He said that after a Thursday truce, "our battle" would begin again early Friday.

While political tension may ease ahead of His Majesty's birthday celebration, protests may resume soon after, said Jade Donavanik, dean of the Graduate School of Law at Bangkok's Siam University.

"This is like pressing the pause button on a movie," Mr Jade said. "You never know from here on whether it will be a happy ending or whether everyone will die at the end."