Kneeling on the sweltering pavement, mourners joined their palms together in the traditional Thai expression of respect as the body of King Bhumibol Adulyadej made the journey from Siriraj Hospital, where he died on Thursday after years of illness, to the Grand Palace for religious rites. Then, they broke down in tears, many sobbing loudly.

All dressed in black, the colour of mourning, they transformed the capital's streets into a sea of black yesterday. Many had waited for hours under the blazing sun.

"Nothing is too difficult if we are doing it for our father," Mr Choosak Boomekbut, 58, told The Straits Times. "He has never stopped teaching us, to love each other, and to be united."

Thailand has known only King Bhumibol, whom the people venerated and called father, in the past 70 years.

It is - at least for now - without a monarch after the heir apparent, Crown Prince Maha Vajiralongkorn, 64, who had been expected to be appointed on Thursday night, asked for time to mourn with the people before ascending the throne.

Under the rules of royal succession, the head of the Privy Council will act as Regent if the throne is vacant.

Thailand had been on tenterhooks in the days leading up to King Bhumibol's death. The revered King, seen as a unifying figure in a kingdom cleaved by political conflict, spent much of his last years in Bangkok's Siriraj Hospital with a range of ailments, including lung infection and renal failure.

Hundreds of those who had gathered at the hospital to pray for his recovery on Thursday returned yesterday to bid him goodbye.

One of the mourners, Mr Sarchai Rajanalapaspreda, 46, had travelled all the way from Nakhon Ratchasima province to witness the procession.

"We don't want this to happen, but at the same time His Majesty is not in pain any more. He is free. So we have to let him go," he said.

"It is only his body that left us. His spirit, his teachings will stay."

The government declared a holiday yesterday on the first day of mourning, though the stock exchange remained open. The benchmark SET Index, which had been in free fall since Monday after the palace released a pessimistic update on the King's health, ended the day 4.59 per cent up.

Thailand, which is currently ruled by a military government, was due to hold elections at the end of next year. It is not clear if these polls may be delayed as a result of the year of mourning declared by the government.

At the Grand Palace, the Crown Prince performed the royal bathing ceremony for his father. This is where King Bhumibol's body will remain for at least 100 days for Buddhist rituals.

Royal funerals can take place months after a death. The last funeral of a member of the royal family was that of King Bhumibol's sister, Princess Galyani Vadhana. She died in January 2008 and was cremated in November that year, after a six-day funeral. Her remains, kept in an urn, were cremated at a specially constructed funeral pyre in Sanam Luang, an open field near the Grand Palace.