LONDON: Queen Elizabeth II's husband Prince Philip spent his 92nd birthday Monday in a London hospital where he is recovering from exploratory abdominal surgery.

The royal patriarch was said by Buckingham Palace to be "progressing satisfactorily" after undergoing the operation at the London Clinic on Friday.

The palace would not reveal if the queen, 87, and other royals were to visit the Duke of Edinburgh, who is expected to spend up to two weeks recuperating in the private London Clinic.

No family visitors have been seen going in to visit the prince, who is renowned for his no-fuss, 'get on with it' attitude.

His birthday was to be marked by traditional royal gun salutes at the Tower of London and Hyde Park.

As per usual, the British flag was flying on government buildings across the country to mark his birthday.

Prime Minister David Cameron sent the prince his best wishes. "Wishing the Duke of Edinburgh a very happy 92nd birthday as he recovers in hospital," he wrote on Twitter.

The analysis of the prince's operation results was expected to be completed this week.

Prince Philip was taken to hospital by car for the planned appointment shortly after attending a Buckingham Palace garden party on Thursday.

Queen Elizabeth spent the weekend at her Windsor Castle residence west of London, having officially opened the BBC's refurbished headquarters on Friday, a few streets away from the London Clinic.

The couple have been married since 1947, making Prince Philip the longest-serving royal consort in British history.

The queen once described him as "my strength and stay all these years".

Prince Philip has now been hospitalised four times in two years, but aides insist he is generally in good health. (AFP)