12/26/2011 09:21 EST | Updated 02/25/2012 05:12 EST

Prince Philip spends 3rd night in hospital

Prince Philip will spend a fourth night in hospital despite making "good progress" in his recovery from surgery to treat a blocked coronary artery, according to a Buckingham Palace spokesman.

The spokesman said Monday the Queen's 90-year-old husband would remain in hospital about 100 kilometres from London "for a short period." It wasn't immediately clear how long that would mean.

"The Duke of Edinburgh continues to make good progress from the procedure. He remains in hospital under observation and in good spirits," said the spokesman, who spoke on condition of anonymity in line with policy.

Philip had a coronary stent implanted on Friday after complaining of chest pains. The surgery was performed at the Papworth Hospital near Cambridge. Papworth is Britain's largest specialist cardiothoracic hospital.

Since then, he has had a steady stream of family visitors. On Christmas Day, six of his grandchildren dropped by to visit, including Prince William and Prince Harry.

The Queen paid a visit on Christmas Eve, along with all four of their children — Prince Charles, Princess Anne, Prince Andrew and Prince Edward.

The Royal Family has been spending the Christmas holiday at the Queen's Sandringham estate, which is about 100 kilometres away from the hospital where Philip is staying.

On Boxing Day, Philip normally leads the family's traditional shooting party on the grounds of Sandringham.