Britain's Queen Elizabeth's doctors are concerned for her health.
Buckingham Palace says it has recommended she remains under supervision.
They say she remains comfortable.
She is at her residence in Scotland.
According to Sky News, Prince Charles, Camilla and Prince William are currently travelling to Balmoral, Clarence House and Kensington Palace said.
Buckingham Palace said in a statement: "Following further evaluation this morning, The Queen's doctors are concerned for Her Majesty's health and have recommended she remain under medical supervision.
"The Queen remains comfortable and at Balmoral."
The whole country will be deeply concerned by the news from Buckingham Palace this lunchtime.
My thoughts - and the thoughts of people across our United Kingdom - are with Her Majesty The Queen and her family at this time.
— Liz Truss (@trussliz) September 8, 2022