Thai mourners praying for the late King Bhumibol Adulyadej take part in the Royal Cremation ceremony in Bangkok, Thailand. Picture: Sakchai Lalit/AP
Thai mourners praying for the late King Bhumibol Adulyadej take part in the Royal Cremation ceremony in Bangkok, Thailand. Picture: Sakchai Lalit/AP
Thai mourners praying for the late King Bhumibol Adulyadej take part in the Royal Cremation ceremony in Bangkok, Thailand. Picture: Sakchai Lalit/AP
Thai mourners praying for the late King Bhumibol Adulyadej take part in the Royal Cremation ceremony in Bangkok, Thailand. Picture: Sakchai Lalit/AP
A mourner cries for the late Thai King Bhumibol Adulyadej at the Siriraj Hospital where he died in Bangkok, Thailand. Picture: Sakchai Lalit/AP
A mourner cries for the late Thai King Bhumibol Adulyadej at the Siriraj Hospital where he died in Bangkok, Thailand. Picture: Sakchai Lalit/AP
In this image made from video, royal dignitaries and foreign leaders attend the funeral and royal cremation ceremony of late Thai King Bhumibol Adulyadej, in Bangkok, Thailand. Picture: Thai Pool via AP
In this image made from video, royal dignitaries and foreign leaders attend the funeral and royal cremation ceremony of late Thai King Bhumibol Adulyadej, in Bangkok, Thailand. Picture: Thai Pool via AP
A Thai mourner weeps while waiting in a line to pay respect to a portrait of late Thai King Bhumibol Adulyadej in a replica of the royal crematorium in Bangkok, Thailand. Picture: Gemunu Amarasinghe/AP
A Thai mourner weeps while waiting in a line to pay respect to a portrait of late Thai King Bhumibol Adulyadej in a replica of the royal crematorium in Bangkok, Thailand. Picture: Gemunu Amarasinghe/AP
Mourners pray during the funeral procession and royal cremation ceremony of late Thai King Bhumibol Adulyadej in Bangkok, Thailand. Picture: Kittinun Rodsupan/AP
Mourners pray during the funeral procession and royal cremation ceremony of late Thai King Bhumibol Adulyadej in Bangkok, Thailand. Picture: Kittinun Rodsupan/AP
The funeral procession of late Thai King Bhumibol Adulyadej begins in Bangkok, Thailand. Picture: Kittinun Rodsupan/AP
The funeral procession of late Thai King Bhumibol Adulyadej begins in Bangkok, Thailand. Picture: Kittinun Rodsupan/AP
The symbolic urn is transported at the funeral procession of late Thai King Bhumibol Adulyade in Bangkok, Thailand. Picture: Kittinun Rodsupan/AP
The symbolic urn is transported at the funeral procession of late Thai King Bhumibol Adulyade in Bangkok, Thailand. Picture: Kittinun Rodsupan/AP
The symbolic urn is transported at the funeral procession of late Thai King Bhumibol Adulyade in Bangkok, Thailand. Picture: Kittinun Rodsupan/AP
The symbolic urn is transported at the funeral procession of late Thai King Bhumibol Adulyade in Bangkok, Thailand. Picture: Kittinun Rodsupan/AP
The royal urn of Thailand's late King Bhumibol Adulyadej is placed on the cremation chamber during the funeral procession in Bangkok, Thailand. Picture: Li Mangmang/Xinhua
The royal urn of Thailand's late King Bhumibol Adulyadej is placed on the cremation chamber during the funeral procession in Bangkok, Thailand. Picture: Li Mangmang/Xinhua
Thai King Maha Vajiralongkorn participates at the funeral procession and royal cremation ceremony of late Thai King Bhumibol Adulyadej in Bangkok, Thailand. Picture: Kittinun Rodsupan/AP
Thai King Maha Vajiralongkorn participates at the funeral procession and royal cremation ceremony of late Thai King Bhumibol Adulyadej in Bangkok, Thailand. Picture: Kittinun Rodsupan/AP
The symbolic urn is transported during the funeral procession of late Thai King Bhumibol Adulyadej in Bangkok, Thailand. Picture: Kittinun Rodsupan/AP
The symbolic urn is transported during the funeral procession of late Thai King Bhumibol Adulyadej in Bangkok, Thailand. Picture: Kittinun Rodsupan/AP

Bangkok - Hundreds of thousands of black-clad mourners crowded Bangkok's historic quarter on Thursday as the cremation of the revered King Bhumibol Adulyadej officially began with Buddhist religious rites and ceremonial candle-lighting by saffron-robed monks.

Many of those lining the Thai capital's streets had slept overnight on pavements near the Grand Palace to capture vantage spots for the funeral procession that wended past buildings draped in yellow marigolds.

"This is the last goodbye," said one tearful visitor, Pimsupak Suthin, 42, who travelled from the northern province of Nan to attend the function. "I really love and miss him. It is very difficult to describe."

King Bhumibol, also known as King Rama IX, died last October aged 88 after ruling for seven decades. He played a pivotal role in maintaining stability during years of political upheaval and rapid development.

At the start of the ceremony, officials dressed in blue and orange removed a symbolic golden urn from the Dusit Maha Prasart Throne Hall and carried it through the streets to a 50-metre-high royal crematorium in a nearby square.

The king's body was moved to the cremation area on Wednesday night from the palace, where it had been lying in state since his death.

New King Maha Vajiralongkorn presided over religious chanting in the afternoon prior to the cremation at the royal crematorium, which features nine spires to mark the reign of his father, the ninth member of Thailand's Chakri Dynasty.

One of the late king's daughters, Princess Maha Chakri Sirindhorn, lit candles inside the crematorium.

Thailand's supreme patriarch, Somdet Phra Maha Muniwong, led the religious ceremony, urging Thais to follow Buddhist teachings and "look beyond sadness".

Royals from Bhutan, Britain, Japan, Lesotho, the Netherlands, Norway, Spain and Sweden, among others, attended the funeral ceremony on Thursday.

Officials in charge of the ceremony said about 110,000 people had gathered near the cremation area, with 200,000 more nearby.

The realisation of the king's departure was now sinking in, said funeral ceremony volunteer Petchpailin Jaidee, 60.

"The cremation makes it real," she added. "I feel like he is truly gone, and it feels like the sky is falling."

A sum of $90 million has been set aside for the funeral, the likes of which has never been seen in Thailand, officials have said, even though King Bhumibol was portrayed as a frugal man despite being one of the world's wealthiest monarchs.

Elsewhere in the Thai capital and around the country, 85 smaller replicas of the royal crematorium and more than 870 pavilions were built for mourners to lay sandalwood flowers and pay their final respects.

Sites to offer sandalwood flowers were also set up in 94 countries to give overseas Thais a chance to say good-bye.

Many onlookers were visibly moved as dozens of men in ancient red garb pulled the golden chariot carrying the royal urn.

Others clutched black and white pictures of the late king and several prostrated themselves as the urn passed by.

"I was very fortunate to have been born under the reign of King Rama IX," said Piyamat Potsopho, 38, adding that she had waited for the funeral procession since Wednesday night.

In Nonthaburi province north of Bangkok, a long queue of black-clad mourners waited to place sandalwood flowers in a mark of respect, as volunteers handed out food.

Analysts say the king's death has left a large vacuum in the Thai psyche.

Thailand has observed a year of mourning and radio and television stations have played songs dedicated to the monarch almost non-stop. The songs urge Thais to follow in "father's footsteps".

King Bhumibol is often referred to as "father" by Thais and is credited with reviving the popularity of the monarchy.

Days of heavy rain failed to deter mourners, many of whom pitched tents to secure the best access to the funeral.

Many businesses around the Southeast Asian nation were shut, while Bangkok's old quarter was draped in garlands of flowers. Some government buildings placed potted marigolds around the portraits of the king.

King Bhumibol was born on a Monday, a day that Thais associate with the colour yellow.