The Mayor of London Boris Johnson said: "London is home to almost half of all people living with HIV in the UK, but a quarter of them are unaware they carry the virus.
"It is vital that people who might be at risk get tested, not only to reduce the risk of transmission to others, but to ensure they get the life-saving treatments that are available."
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Eyewitnesses say a car veered across the road and mounted the pavement near Beavers Community Primary School in Hounslow, west London.
Inspectors also found the electric meter had been bypassed to avoid paying for electricity.
Anthony Birdee from Deptford in south east London tied the English bull terrier, named Muller, to a post in his garden.