Prince Philip admitted to hospital as 'precautionary measure,' Buckingham Palace says

The Duke of Edinburgh, Prince Philip, has been admitted to hospital as a "precautionary measure", Buckingham Palace has announced.

He is expected to remain there "for a few days of observation and rest".

In December 2019, the Duke spent four nights at the private hospital for treatment for a pre-existing but undisclosed condition.

In June 2016 he pulled out of a Battle of Jutland anniversary event citing a minor ailment which was followed soon after by his retirement from public duty in 2017.

Prince Philip's hospitalization was not an emergency admission and he walked into the hospital unaided, a royal source told ABC News.

On the advice of his doctor, the Duke of Edinburgh was taken to King Edward VII hospital in London.

Queen Elizabeth and the prince have been staying at Windsor Castle, west of London, during Britain's coronavirus pandemic.

Concerns for the British royal's health have been raised in recent years.

In January 2019, he emerged unscathed after his vehicle was involved in a traffic accident that injured two people near the monarch's Sandringham estate in eastern England. Philip needed help to get out of the Land Rover but wasn't injured. Prince Philip was seen by a doctor as a precaution while the driver of the other auto sustained cuts and a passenger broke her wrist. He does not have a Covid-19 related illness, the source added. Elizabeth became queen in 1952, following the death of her father, King George VI.