Sunday’s event took place a few days after the queen’s birthday on 12 August, which is also a national holiday and celebrated as Mother’s Day in Thailand.
Last week the palace announced its latest update on the king’s health, saying he was recovering from several ailments including excess fluid on the brain and difficulty breathing due to congested lungs. Last October he had his gallbladder removed.
The king has rarely left a Bangkok hospital that has become his residence since he was admitted in 2009 with what was said to be a lung inflammation. The queen has also seldom been seen in public since suffering stroke-like symptoms in 2012.
Most Thais hold great affection for Bhumibol, who took the throne in 1946 and is the world’s longest-reigning monarch.