Thailand's King Bhumibol Adulyadej is improving following an operation at a Bangkok hospital to remove his gallbladder, the BBC reported Monday.
A royal palace statement said surgeons removed the king's gallbladder on Sunday night after it was found to be swollen.
"The operation was satisfactory and His Majesty returned to his room at 20 minutes past midnight. This morning the heartbeat has lowered, blood pressure is normal and His Majesty's fever is lower," the statement said.
The king is often seen as a unifying force in Thailand which has seen political deadlock in recent years.