Queen Elizabeth's 91-year-old husband Prince Philip, who has been admitted to hospital after a recurrence of a bladder infection, is responding well to treatment, Buckingham Palace said on Thursday.
Philip, the Duke of Edinburgh, was taken to hospital for the third time in eight months on Wednesday while he and the queen were staying at Balmoral, their Scottish royal residence. He was taken to Aberdeen Royal Infirmary.
"The Duke of Edinburgh is responding well to treatment. It is unclear when he'll be discharged but is likely to remain in hospital for a few more days," a palace spokesman said.
Philip first required treatment for a bladder infection in June during celebrations to mark his wife's 60 years on the British throne.
That occurred a day after he had braved terrible weather conditions to watch a 1,000-boat flotilla on the River Thames from a royal barge. He was then unable to attend other events including a thanksgiving service for the queen at St Paul's Cathedral.
Last Christmas, he spent four days in hospital and had an operation to clear a blocked artery in his heart after suffering chest pains.
The sprightly prince has continued to carry out royal duties. He accompanied the queen to the opening ceremony of the London Olympics at the end of July and attended a yachting event on the Isle of Wight, off southern England, on Monday.