Bangkok: Thailand's King Bhumibol Adulyadej, the world's longest-reigning monarch, has died after a long illness, plunging his south-east Asian country of 64 million people into a period of intense mourning and uncertainty. He was 88.
Thai television interrupted programming to make the announcement shortly before 7pm Thai time.
Prime Minister Prayuth Chan-ocha announced that Crown Prince Maha Vajiralongkorn will succeed his father.
"The government will proceed with the succession. The government will inform the National Legislative Assembly that his Majesty the King appointed his heir on December 28 1972," Mr Prayuth said. The assembly was due to meet Thursday evening.
Mr Prayath said there would be a 12 month mourning period and flags would fly at half mast for 30 days. He said there could be no celebratory events held for 30 days, indicating there will be restrictions on bars and the selling of alcohol.
Revered by Thais, the king succeeded to the throne on June 9, 1946, when he was a gangly, thick-spectacled American-born 18-year-old who could barely speak Thai.
During 70 years on the throne he presided over the revival of a faltering centuries-old royal institution, growing in power and influence as he helped direct Thailand's social and economic development.
Thailand's National Assembly ended an extraordinary session late Thursday night without inviting a successor to the king to ascend to the throne.
"We are preparing the next moves," said a spokesman for the assembly, which is made up of military appointees. Assembly members wore black and stood in silence for nine minutes.
It is likely to be months before the Crown Prince's coronation as the new monarch,as Thailand goes through a period of intense national mourning.
Many businesses are expected to be closed or provide reduced services as Thais mourn the loss of the ninth Chakri king, whom many regard as semi-divine.
Western diplomats in Bangkok say tourists and expatriates in Thailand should wear black and respect the grief Thais will be feeling for their king, whose portrait hangs in every government building and in many shops and homes.
People in a crowd that had gathered at Bangkok's Siriraj hospital, where the king has been battling ailments for several years, openly wept as news of the death swept social media.
"Long live the King! Long live the King!" they cried, gazing up at the hospital building with tear-filled eyes.
Dozens of doctors wearing white coats solemnly sang the Thai national anthem in the hospital's foyer. One women wearing pink, a colour royal astrologists said was good for the king, collapsed hysterically in the hospital grounds holding photograph of the king and queen. But a Reuters reporter said most of the people at the hospital were dignified.
Four of the king's children, including 63-year-old Crown Prince Maha Vajiralongkorn, were at the hospital Thursday evening. The Crown Prince arrived in the country on Thursday from Germany where he owns a lakeside villa.
King Bhumibol had been treated for various ailments during a year-long hospitalisation in the Thai capital. He had not made a public appearance since January 2016.
Anxiety over his health and eventual succession has formed the backdrop to more than a decade of bitter political division in Thailand that has included military takeovers and sometimes violent street demonstrations.
The death follows a coup in May 2014 that toppled the democratically-elected government of Thailand's first female prime minister, Yingluck Shinawatra.
King Bhumibol acceded to the throne after the mysterious shooting death of his brother, King Ananda Mahidol, at the Royal Palace in Bangkok on June 9, 1946.
Born in Cambridge, Massachusetts, where his father was studying, King Bhumibol, whose name means "Strength of the Land, Incomparable Power", was educated in Switzerland before returning to Thailand to be crowned on May 5, 1950, with a promise to the nation: "We shall reign with righteousness, for the benefit and happiness of the Siamese [Thai] people."
He had married Queen Sirikit - then a 17-year-old student - a week earlier, and they had four children, one son and three daughters.
The queen, who turned 84 in August 2016, has also suffered ailments and hospitalisation in recent times.
News about the royal family is tightly controlled in Thailand, where laws protecting the royals from insult make it a crime to defame, insult or threaten the king, queen, heir to the throne or regent.
Former army chief and now Prime Minister Prayuth Chan-ocha warned when he led the 2014 coup that anything deemed "offensive" to the monarchy would be dealt with harshly under the country's lese-majeste laws.
Lindsay Murdoch is a three-time winner of the Walkley Award, Australia's top award for journalistic excellence. Lindsay is a former correspondent based in Singapore, Jakarta and Darwin. In 1999 he covered the tumultuous events in East Timor, and in 2003 he covered the Iraq war while embedded with US Marines.