Newcastle University's Conor O'Neill, who carried out research into the effects of a bomb blast inside a train carriage, said using special materials could prevent shrapnel injuring passengers.
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The 47-year-old man died shortly after 3pm on Tuesday.
Specialist explosive detection dogs searched through the town examining letter boxes and phone booths for signs of potential devices.
Temperatures reached 29.1C in St James's Park, central London.