Thailand's King Bhumibol Adulyadej has asked the nation to work together for stability, as protests give way to celebrations as people marked the monarch's birthday.

Cheering crowds lined the streets to celebrate the 86th birthday of Thailand's revered king near his seaside palace on Thursday, an event marked with a lull in tensions after violent political protests.

"To bring happiness to this country, everyone has to do the right thing," the king said in his brief address.

"We have our duty and we all know our roles.For the benefit of our country, Thai people must be aware and must pay attention to this duty, for the good of the nation and its security."

Thailand remains on edge following days of street clashes between police and protesters bent on overthrowing Prime Minister Yingluck Shinawatra and curbing the political influence of her brother Thaksin.

Protesters and police in Bangkok observed a temporary truce Wednesday in a dramatic move ahead of the birthday celebrations for King Bhumibol, who is treated as a near-deity by many Thais.

Images broadcast live on all Thai television stations showed a sea of yellow, as thousands of people lined the streets wearing the colour associated with the king in the central coastal town of Hua Hin, where he has lived since leaving hospital in August.

Weeping supporters shouted "long live the King!" and waved Thai national flags as the royal convoy made a brief tour of the town's streets before returning to the palace.

Protests to resume

"He's given his personal time to help his people unconditionally and asks for nothing in return," crowd member Surin Ruengpanich told Al Jazeera.

Crown Prince Maha Vajiralongkorn made a speech to begin the formal birthday ceremony, which was presided over by the frail monarch and attended by dignitaries including Yingluck and the country's military heads.

Thailand has been periodically rocked by sometimes bloody unrest since former premier Thaksin was deposed by royalist generals in a coup seven years ago.

Demonstrators cleaned up a key rally site in old Bangkok in preparation for the birthday festivities, vowing to pause in reverence on Thursday but to resume their street action on Friday.

King Bhumibol, the world's longest-serving monarch, has suffered from a range of ailments in recent years, but left the Bangkok hospital where he had lived since 2009 to move to his palace in Hua Hin with Queen Sirikit earlier this year.

Any political action or violence on his birthday would be viewed as a serious sign of disrespect.

Police fired tear gas, rubber bullets and water cannon to repel protesters trying to occupy key ministries in the unrest at the weekend, which left five dead and over 200 injured.

The long-running political conflict broadly pits a Bangkok-based middle class and royalist elite backed by the military, against rural and working-class voters loyal to Thaksin, a billionaire businessman-turned-populist politician.

The recent protests mark the biggest clashes since dozens of people were killed in a crackdown on mass pro-Thaksin rallies in Bangkok three years ago.

The demonstrations are aimed at toppling Yingluck's government and replacing it with an unelected "people's council".

They were triggered by an amnesty bill, since abandoned by Yingluck's ruling party, which opponents feared would have allowed Thaksin to return to his home country.

He fled in 2008 to avoid jail for a corruption conviction he contends is politically motivated.