Bangkok: The health of Thailand's King Bhumibol Adulyadej is "still unstable", the palace said on late Wednesday, with the 88-year-old on a ventilator and battling a new infection as crowds gathered to pray outside his Bangkok hospital.
Bhumibol is the world's longest-reigning monarch and beloved by many in Thailand, where he is seen as a rare unifying figure in a country riven by political rivalries.
But he has not been seen by the public for nearly a year as he battles a series of ailments in a Bangkok hospital, a source of great anxiety for many in the kingdom.
In a fresh palace health update released on Wednesday evening, blood tests on Tuesday showed the king's liver was working "irregularly" and that there was heightened levels of uric acid in his blood.
Doctors prescribed antibiotics for an infection, placed him on a ventilator and are using Continuous Renal Replacement Therapy to help lower acid levels, the statement said.
"His illness overall is still unstable," it added.
The statement followed a similarly pessimistic palace health update on Sunday that triggered market jitters inside Thailand this week as well as public prayers for his well-being.
By late evening around 300 well-wishers had gathered outside Siriraj Hospital where the king has spent much of the past two years.
Many held aloft portraits of the king and were moved to tears by a week of grim news.
"It feels like he is getting worse this time," said Somchit Naravichit, 58, tears welling in her eyes.
"Millions of Thais are sending him support, praying for him and wanting him to get well soon," she said.
Stock market volatility hit Thailand for a third day on Wednesday, plunging as much as 6.8 per cent after junta chief General Prayut Chan-O-Cha abruptly cancelled a visit outside the capital with little explanation.
The market later recovered to close 2.5pc down. But rumours about the king's health swirled on social media.
By late afternoon junta officials downplayed Prayut's schedule interruption saying he had returned to the capital to meet with named heir Crown Prince Maha Vajiralongkorn, who spends much time outside the country.
Junta spokesman Lieutenant General Sansern Kaewkamnerd said the trip cancellation was to provide the Crown Prince with "a routine presentation on the government's work".
Most Thais have known no other monarch and many revere Bhumibol as the kingdom's moral leader.
Vajiralongkorn, 64, has yet to attain his father's widespread popularity.
Since Sunday's announcement, many Thais have started wearing pink in the belief it will bring the king good luck.
Security was stepped up at the riverside hospital where Bhumibol is being treated, with a spokeswoman saying they expected the Crown Prince to make an imminent visit to see his father.
"The king is very important to us because he has done everything for the people," Suwanna Kaennumtiang, a 62-year-old woman holding a portrait of the king, said.
"He is like my angel. I pray to his photo on my bedside everyday."