BANGKOK, Thailand -- Thailand's revered King Bhumibol Adulyadej marked his 86th birthday on Thursday with a call for national unity and stability, but offered no further guidance on how his polarized nation might find its way out of its bitter political standoff.
Many people had hoped the visibly infirm king would use his annual birthday speech to step in -- as he has in the past -- to broker peace in the conflict that has led to street fighting by anti-government mobs seeking to occupy the prime minister's office and other official buildings.
The protesters and the government of Prime Minister Yingluck Shinawatra called a truce in their battling as a mark of respect for the monarch. The violence has killed five people and wounded at least 277 since last weekend.
Protest leader Suthep Thaugsuban said the truce would end Friday.
Onlookers wept as the king delivered his brief address with great effort in a weak gravelly voice, pausing for long periods of time.
"Our country has long experienced happiness because we have been united in performing our duties and working together for the good of the whole country," said the king, garbed in a ceremonial golden robe and sitting on a throne.
"All Thais should consider this very much and focus on doing their duties ... which are the security and stability of the country," he said.
The king's appearance renewed concern about his health and whether he physically is able now to help heal the country's divide.
As a constitutional monarch, he has no official political role, but no other person commands the same moral authority. He has in the past made high-profile interventions in situations where the country seemed on the verge of violently splitting apart.
The many prominent people in attendance at Thursday's speech -- the privy councillor, the prime minister and Cabinet members, opposition leader and senior statesmen -- looked sombre and troubled by the king's appearance.
"I think these people are quite worried, quite worried for the king, quite worried for the country," said Charnvit Kasetsiri, a senior Thai historian.
The current standoff results from years of enmity between supporters and opponents of Yingluck's brother, former Prime Minister Thaksin Shinawatra, who was ousted in a 2006 military coup after being accused of corruption and disrespect for the king.
Thaksin, a billionaire, fled overseas to avoid a corruption conviction, but critics say he still controls Thai politics through his sister and his political machine.
The contending parties are likely to draw their own interpretations of the king's speech, analysts said.
"It's rather neutral, so whether it's relevant to the present crisis depends on your interpretation," Charnvit said.
Kevin Hewison, a Thai politics scholar at Australia's Murdoch University, described the king's remarks as "pretty much his stock speech over several decades."
"It is an essentially conservative message that may have some resonance at this time, and I expect both sides to claim that the message needs to be heeded by the other side," he said.
The king's infirmity also uncomfortably raised the seldom-addressed inevitable transition of royal power. In July he ended a nearly four-year hospital stay -- initially for treatment of a lung infection -- to live at a palace in the seaside town of Hua Hin, where he delivered his speech.
His heir apparent, Crown Prince Vajiralongkorn, played a prominent role in Thursday's ceremony.
The queen, who has also been in poor health, was not present. She is thought to be sympathetic to the anti-Thaksin movement. Royalists -- generally opposed to Thaksin and his political machine -- worry that the crown prince may lack the moral stature to effectively take over his father's job.
Both pro- and anti-Thaksin camps want to be in power when the transition occurs so they can influence it.
The anti-government protesters, associated with the opposition Democrat Party, seek to force Thaksin's sister out of power and change the country's democratic system of government. They have little chance of winning a national election because of widespread support for Thaksin in the countryside.
As the king spoke, protesters watching the event in Bangkok on large outdoor TV screens heckled and cursed when the picture showed Prime Minister Yingluck.
"Today is a day that Thai people nationwide believe is an auspicious day," protest leader Suthep said after watching the speech. "Tomorrow the people's movement will continue to eradicate the Thaksin regime from Thailand."
In Hua Hin, crowds dressed in yellow, the royal colour, lined the roads to catch a glimpse of the world's longest reigning monarch. They shouted "Long live the king!" as his motorcade drove slowly to Klai Kangwon Palace, which literally means "Far From Worries."
Associated Press writers Jocelyn Gecker and Jinda Wedel contributed to this report.
