"His Majesty has undergone physiotherapy and has been given intravenous saline as well as medicine," said the bureau.

Princess Ubolratana Rajakanya, who left the hospital in the early evening, said the King could talk and eat soft food.

"His Majesty is so delighted to see many well-wishers," the Princess said after greeting and talking to some of the well-wishers.

As she was giving an interview to reporters, HRH Crown Prince Maha Vajiralongkorn, the Royal Consort HRH Princess Srirasmi and HRH Prince Teepangkorn Rasmichoti arrived at the hospital. All were dressed in yellow.

Princess Ubolratana kissed the Crown Prince on the cheek before leaving.

In the afternoon, the King instructed bureau officials to send vases of flowers he had received to other patients at the hospital to wish all of them a quick recovery. He also had vases of flowers sent to the hospital staff to offer them moral support in carrying out their duties.

Chaipattana Foundation secretary-general Sumet Tantivejkul said His Majesty would likely carry out duties when he regained his health. "His Majesty has always said he wants to go to a few places. That means he wants to work on some projects there," he said after signing a get-well message.

The King established the foundation to handle development projects for the benefit of his people.

Meanwhile, in another part of the hospital, hundreds of people clad in yellow crowded together at the Centennial Pavilion to sign their get-well messages to His Majesty in special books prepared by the bureau.

The increasing number of well-wishers prompted officials to open the books for signing earlier than initially scheduled.

HRH Princess Maha Chakri Sirindhorn also greeted some well-wishers after she paid respect to the statues of her late grandparents - HRH Prince Mahidol Adulyadej of Songkhla and HRH Princess Sri Nagarindra, the Princess Mother - in the hospital's compound.

Pensri na Ayutthaya, 81, said she had travelled from Nakhon Pathom to the hospital because she wanted to offer moral support to His Majesty. She said she planned to stay until His Majesty was discharged from the hospital.

"His Majesty has worked so hard for his people. I love His Majesty a lot," the elderly woman said.

Many high-profile figures such as caretaker Prime Minister Thaksin Shinawatra and his wife Pojaman, former PM Anand Panyarachun, Bangkok Governor Apirak Kosayodhin, Thanpuying Boonruen Choonhavan, Thanpuying Chongkol Kittikachorn and Constitution Court president Ura Wang-ormklang also signed messages to the King.

Books for people to sign get-well messages for His Majesty have been opened at many locations around the country, including all district offices in Bangkok, the Criminal Court and at Royal Thai Army units.