BANGKOK (REUTERS) - Thailand's King Maha Vajiralongkorn on Wednesday (Oct 18) presided over a ceremony marking the end of the construction of the royal crematorium that will be used in the funeral of his father, the late King Bhumibol Adulyadej, on Oct 26.

The king blessed and then raised the Nine-Tiered Great White Umbrella of State, the most sacred regalia of the Thai monarchy, to the top of the lavish crematorium - the main site of the royal funeral that was built from scratch on an open space in front of the Grand Palace in Bangkok's old quarter.

Artisans have worked for 10 months to build the site that includes eight structures decorated with ornaments of various gods and goddesses, mimicking a vision of heaven in Bhramin-Buddhist traditions of Thailand's royal court.

Hundreds of thousands of black-clad mourners are expected to camp for days near the palace to observe the five-day funeral ceremony, a last goodbye to much-loved King Bhumibol who reigned over Thailand from 1946 until his death on Oct. 13, 2016.

Foreign Minister Don Pramudwinai said at least 30 foreign dignitaries will attend the royal cremation and the number could rise.

The dignitaries who have confirmed their attendance include King Jigme Khesar Namgyel Wangchuck of Bhutan, Queen Maxima of the Netherlands, Queen Mathilde of Belgium, Crown Prince Haakon of Norway, Japan's Prince Akishino, Australia's Governor General Sir Peter Cosgrove and Singapore's President Halimah Yacob.

About 12 million people, or almost one sixth of Thailand's population, have paid their respects to the late king, queuing up to visit the Grand Palace where he has been lying-in-state.

Oct 26 has been declared a national holiday. That night, more than 3,000 performers will join a final tribute of music and puppet shows to end a year of mourning.