Queen Elizabeth II's doctors are concerned for her health, Buckingham Palace says; family fly in to be by her side

LONDON — Doctors are concerned for the health of Britain's Queen Elizabeth II and have advised that she remain under medical supervision, Buckingham Palace said Thursday.

Immediate family members have been informed and are currently traveling to Balmoral Castle, the queen's royal residence in Scotland.

"Following further evaluation this morning, The Queen's doctors are concerned for Her Majesty's health and have recommended she remain under medical supervision," Buckingham Palace said in a statement.

It added that the queen, 96, remains comfortable and at Balmoral.

The heir to the throne Prince Charles, the Duke of Cornwall, and his wife, Camilla, the Duchess of Cornwall, have now arrived at Balmoral.

The queen's other three children, Princess Anne, Prince Andrew, and Prince Edward, as well as her grandson Prince William, the Duke of Cambridge, have also arrived.

Prince Harry and and his wife Meghan, the Duke and Duchess of Sussex, are on their way.

Princess Kate, the Duchess of Cambridge, has remained in Windsor as Prince George, Princess Charlotte and Prince Louis are on their first full day at their new school, Kensington Palace said.

The queen, who is the world's longest-serving monarch, has reportedly been suffering from deteriorating health for the past several months, with doctors citing ongoing "episodic mobility problems."

She spent a night in hospital last October and has been forced to cut back on her public engagements since then. She has been on vacation at her Scottish estate since late-July.

On Tuesday, the queen broke with tradition and appointed her 15th prime minister from Balmoral rather than traveling to Buckingham Palace, as is typical. She was also forced to cancel a planned virtual meeting with senior ministers after being advised to rest by her doctors.

Britain's new Prime Minister Liz Truss, who met with the queen Tuesday, said her thoughts were with her and her family.

"My thoughts — and the thoughts of people across our United Kingdom — are with Her Majesty The Queen and her family at this time," she said.

The BBC, the U.K.'s national broadcaster, suspended all regular programming until 6 p.m., local time, following the news.

Keir Starmer, the leader of Britain's opposition Labour Party, said he was deeply concerned about the news.

"Along with the rest of the country, I am deeply worried by the news from Buckingham Palace this afternoon," he said in a statement.

Scotland's First Minister Nicola Sturgeon said she was "profoundly concerned" and Wales' First Minister Mark Drakeford sent his best wishes on behalf of the people of Wales.

The news of the queen's ill-health came as members of parliament were gathered in the House of Commons to hear details of the government's plan to help households and businesses with rising energy costs.

Cabinet minister Nadhim Zahawi was seen entering the Chamber during the meeting and speaking urgently to Truss. Notes about the developing situation were also passed to the Commons speaker and the Labour leader.

Elizabeth has been queen of Britain and more than a dozen other countries since 1952. Earlier this year she celebrated her 70th year on the throne.

Her husband Philip, the longest-serving royal consort in history, died last year aged 99.