Queen's well-wishers gather at Balmoral Castle: 'Something serious going on'

Hundreds of Queen's well-wishers have gathered outside the gates of Balmoral Castle in Aberdeenshire amid deep concerns over the Queen Elizabeth's health.

Doctors are "concerned for Her Majesty's health," a statement from Buckingham Palace said. 

"The careful wording of the palace statement suggests something serious is possibly going on", says former BBC royal correspondent Richard Sumner.

"When you're 96, of course you can’t expect to have the health of a 25-year-old. Hopefully this is a passing storm that can be overcome but I think that judging from the careful wording of the palace something serious is possibly going on here," Summer added.

"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," according to the statement from Buckingham Palace.

Prince Charles, Camilla, Prince William and other senior royals have arrived at the Balmoral Castle 

Leader of the Democratic Unionist Party in Northern Ireland, Sir Jeffrey Mark Donaldson, has tweeted out his reaction.

Former Conservative prime minister David Cameron has tweeted his "deep concern" at the news.