The Duke of Edinburgh has been admitted to hospital after feeling unwell, Buckingham Palace said.
Philip, aged 99, who received a Covid-19 jab in January, was admitted to the private King Edward VII Hospital in London on Tuesday.
In a statement, Buckingham Palace said: “His Royal Highness The Duke of Edinburgh was admitted to the King Edward VII Hospital in London, on Tuesday evening.
“The Duke’s admission is a precautionary measure, on the advice of His Royal Highness’s Doctor, after feeling unwell.
“The Duke is expected to remain in hospital for a few days of observation and rest.”
Downing Street said Boris Johnson sends his best wishes to the Duke of Edinburgh.
A No 10 spokesman said: “The PM sends his best wishes to the Duke of Edinburgh as he undergoes a few days of rest in hospital.”