Doctors concerned for Queen's health - Buckingham Palace
The Queen is under medical supervision at Balmoral after doctors became concerned for her health, Buckingham Palace has said.
"Following further evaluation this morning, the Queen's doctors are concerned for Her Majesty's health and have recommended she remain under medical supervision," a statement said.
"The Queen remains comfortable and at Balmoral."
Prince Charles is now with her and the Duke of Cambridge is on his way.
The Duchess of Cornwall has also travelled to Balmoral.
The announcement comes after the Queen, 96, pulled out of a virtual Privy Council on Wednesday, with doctors advising her to rest.
Prime Minister Liz Truss said the "whole country" would be "deeply concerned" by the news.
"My thoughts - and the thoughts of people across our United Kingdom - are with Her Majesty The Queen and her family at this time," she added.
The Queen appointed Ms Truss as prime minister at Balmoral on Tuesday, instead of travelling to London for the event.