Queen Elizabeth’s husband, Prince Philip, was admitted to a hospital in London after reportedly telling attendants that he was not feeling well. Buckingham Palace released a statement to confirm initial reports.

The 99-year-old member of the British royal family was admitted to the King Edward VII Hospital in London on Tuesday, the statement said.

Sources with knowledge in the matter said that the Duke of Edinburgh was taken to the hospital by car and that it was not an emergency admission. The same sources said that Prince Philip was still able to walk into the hospital unaided.

Prince Philip’s illness is reportedly not COVID-19 related. Queen Elizabeth reportedly did not accompany him to the hospital. The Queen reportedly remains at Windsor Castle in West London.

Buckingham Palace said that the Prince’s admission was a “precautionary measure” and ordered by his doctors.

“The Duke is expected to remain in the hospital for a few days of observation and rest,” the Buckingham Palace press release said.

Since he decided to step back from public life in 2017, Prince Philip has been taken to the hospital several times. In 2019, the Duke was admitted to the hospital to undergo treatment for a pre-existing condition.

The Duke and the Queen have spent most of their together at Windsor Castle since the start of the pandemic last year. Last month, they both received their first dose of a coronavirus vaccine.