Queen Elizabeth will no longer attend Friday's Service of Thanksgiving for her seven decades as monarch after experiencing some discomfort when she appeared at a military parade on Thursday, Buckingham Palace said.
The queen had been due to attend the service at St Paul's Cathedral on the second day of celebrations for her Platinum Jubilee.
Earlier on Thursday she appeared on the balcony of Buckingham Palace, waving to thousands of well wishers.
(Reporting by Kate Holton)