In a rare public appearance, Thailand's king has called for unity and stability in the divided nation during a speech to mark his 85th birthday.

Vast crowds of devoted Thais turned out on Wednesday in Bangkok for a brief glimpse of King Bhumibol Adulyadej.

Bhumibol sat on a throne on a balcony overlooking a plaza with a crowd that police estimated at 200,000 as he delivered a brief homily on national harmony.

Most in the crowd were dressed in the royal colour of yellow, many waving Thai flags and flags adorned with the king's insignia.

The turnout was a vivid demonstration of the affection in which many hold for Bhumibol, despite political turmoil in recent years that has raised doubts about the future of the monarchy.

Bhumibol's family flanked him for part of his appearance, including Crown Prince Vajiralongkorn, his son and heir-apparent.

Deteriorating health

The king, who is seen as almost a demi-god by many in the politically turbulent nation, told the crowd that the "goodwill" Thais had shown by attending the ceremony together "gives me the confidence that your kindness is key to bringing unity to the people and the nation".

Chants of "Long live the king!" followed the royal motorcade as it made its way to and from the hospital where Bhumibol' has lived for three years since suffering a respiratory illness in 2009.

Al Jazeera's Wayne Hay, reporting from Bangkok, said Bhumibol's deteriorating health has forced him to reduce the number of public appearances he makes.

"In recent years those general public appearances by the king have been less frequent," he said.

"As each year passes concern grows about the health of their beloved king."

Bhumibol, whose 66 years of service makes him the world's longest reigning monarch, suffered a minor brain bleed in July, but has since made several official appearances.

Extremely sensitive

Any discussion of the royal family is extremely sensitive in Thailand, where the palace has been silent over the organisation of an eventual succession.

The kindgom is in the grip of a long-running political crisis pitting royalists against supporters of Thaksin Shinawatra, the deposed prime minister, and the current government led by his sister Yingluck.

The bitter divisions have led to sometimes violent street rallies in recent years.

An anti-government protest last month - attended by members of the influential monarchist "Yellow Shirts" - was centred at Royal Plaza and saw clashes between police and demonstrators in the city.

Yingluck was among the dignitaries at the ceremony, as well as most key members of the royal family with the exception of Queen Sirikit.

Doctors treating the 80-year-old queen, who was diagnosed with a slight loss of blood flow to the brain after being taken ill in July, said she was still too weak to attend the event, according to a statement from the palace on
Tuesday.

Source: Al Jazeera And Agencies