BANGKOK: Thailand put politics aside on Thursday to honour the country’s revered monarch, as people of all political persuasions waited to hear if their king would offer advice in his annual birthday speech to help resolve a crisis that divided the nation.

Violence and street battles between anti-government protesters and police were put on hold as both sides observed a truce to mark the 86th birthday of King Bhumibol Adulyadej, who has often served as a unifying figure in times of crisis.

Vast crowds dressed in the royal colour of yellow lined the roads in the seaside town of Hua Hin, where the king was to deliver a speech as part of his traditional birthday ceremonies.

Many people are hopeful the king can step in as he has done before to ease the current standoff, which results from years of enmity between supporters and opponents of former Prime Minister Thaksin Shinawatra. Mr. Thaksin was deposed by a 2006 military coup after being accused of corruption and disrespect for the king.

As a constitutional monarch, the king has no official political role, but no other figure commands the same moral authority or the same loyalty from the armed forces in the coup-prone country.

On two occasions when the country seemed to be coming apart, his intervention turned the tide, restoring peace literally overnight.

When a pro-democracy uprising against a military dictatorship in 1973 left Bangkok in a state of anarchy, with the army ready to unleash a bloodbath, he showed support for the demonstrators and persuaded the dictators to go into exile.

A similar disaster was avoided in 1992 during another mass protest against a military-backed government. After a crackdown threatened to spin out of control, the king summoned the protest leader and the prime minister to a late-night televised meeting where he chastised them for tearing apart the nation.

The latest conflict is far less severe, but it is violent and seemingly intractable.

Traditionally the king speaks his mind during his birthday speech, one of the rare occasions on which he talks directly to the public. He often makes his points through humor and aphorisms, but their meaning is usually clear.

Sukanya Chaisilapin, 27, an employee for a courier company, said she thought his speech “will be a way out.”

“Previously his majesty has given speeches about reconciliation and unity, and it could help with this kind of situation,” she said.

The king is a less vigorous figure than he used to be. In July, he ended a nearly four—year hospital stay initially for treatment of a lung infection to live in a palace in the seaside town of Hua Hin, where he is to deliver his speech.

The monarchy, once an untouchable institution, has also fallen in esteem in recent years after being abused for political gain by different parties.

Those who sought to oust Mr. Thaksin accused him of trying to usurp the king’s authority, and some alleged that he sought to establish a republic.

The 2006 coup that toppled Mr. Thaksin polarised Thailand. He had won the support of the country’s urban poor and rural majority by implementing populist programs such as cheap health care, while many in the urban-based elite see Mr. Thaksin as a corrupt threat to their privileged positions and to the monarchy.

Mr. Thaksin’s supporters believe the king’s top adviser helped arrange the 2006 coup. While the king kept out of the fray, his wife, Queen Sirikit, made a show of support in 2008 for anti-Thaksin demonstrators, creating the perception that the palace had cast its lot with one faction.

Political street fighting that had wracked pockets of Bangkok since the weekend ended abruptly Tuesday ahead of the birthday celebrations. The protesters are seeking to bring down the government of Mr. Thaksin’s sister, Prime Minister Yingluck Shinawatra, and institute an unelected “people’s council” to administer the country.

Although police have stood aside the last several days and let protesters enter public buildings the last several days, earlier violence killed five people and wounded at least 277 since the weekend.

Protest leader Suthep Thaugsuban has vowed to keep up the struggle to topple Ms. Yingluck, saying that “our battle” will resume Friday.