Police are looking into possible links with another stabbing in South London on Friday. The incident happened around lunchtime in West Norwood. A 17 year old was injured and is in a stable condition in hospital.
One man has been arrested over this attack, and continues to be questioned by police.
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Specialist explosive detection dogs searched through the town examining letter boxes and phone booths for signs of potential devices.
Temperatures soared to 27.9C in Northolt shortly after midday on Thursday, making it the warmest April day for 69 years.
The South East will enjoy the best of the weather and along with Paris will be the hottest place in Europe.