Thailand's 81-year-old King Bhumibol Adulyadej, the world's longest-serving monarch, has been hospitalised. Prime Minister Abhisit Vejjajiva gave this information while talking to newspersons in Bangkok on Sunday. He said that doctors at Siriraj Hospital said the king's health gave no cause for concern, but he did not describe the ailment.A hospital spokeswoman confirmed to Associated Press that the king had been admitted, but gave no further details.Reports say that the king's health is an extremely sensitive topic in Thailand because of concerns that the succession may not go smoothly.