Britain's Prince Philip is being looked after "very well", his son Prince Charles said Monday after the elderly royal spent a third night in hospital for treatment for a pre-existing condition.
"He's being looked after very well in hospital. At the moment that's all we know," Charles told a reporter when asked about his father's health during a visit in northern England.
Philip, the 98-year-old husband of Queen Elizabeth II, was admitted to London's King Edward VII hospital on Friday.
Buckingham Palace said it was for "observation and treatment in relation to a pre-existing condition", adding that it was a "precautionary measure".
The Duke of Edinburgh was reportedly flown there by helicopter from the royal Sandringham estate in eastern England, where he has been based since retiring from public duties in 2017.
The 93-year-old queen did not alter her plans, travelling by train on Friday from London to Sandringham, where she hosts the royals for Christmas each year.
She attended church at usual on Sunday, accompanied by her son Prince Edward and his family.
The duke has long been an advocate of eating well and keeping fit, but has had a number of health issues as he advances in age.
The Sun tabloid reported that Philip has suffered a month of ill-health, including a "bad fall" which left him confined to bed for a couple of days.
In recent years, he has been admitted to hospital for abdominal surgery, bladder infections and a blocked coronary artery, while he is also reported to suffer from arthritis in his right wrist.
In January, the duke was involved in a car crash near Sandringham. He pulled out onto a main road, hitting another car and flipping his Land Rover.
A woman in the other car broke her wrist, for which Philip apologised. He subsequently gave up his driving licence, but faced no further action.