George Bush Sr has been moved into intensive care after suffering "a series of setbacks that include a persistent fever," according to a family spokesman.
Doctors are "cautiously optimistic" about the 88-year-old former president's health, he added.
Video report by Debi Edward.
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The 1D star will go ahead with his scheduled performance as per the wishes of his late mother, Johannah Deakin, who passed away on Friday.
Michael Gove admitted he made "mistakes" in his bid for the Tory Party leadership, and Theresa May was right to drop him from her cabinet.
Four people have been killed and at least 12 injured after a cargo train carrying propane-butane derailed and exploded in Bulgaria.