Security personel stand guard outside Waterloo station in central London on March 5, 2019, following a report of a suspicious package at the station. – Three small improvised explosive devices were found at buildings at Heathrow Airport, London City Airport and Waterloo train station in what the Metropolitan Police Counter Terrorism Command said was being treated as a “linked series”. (Photo by Tolga AKMEN / AFP) British counter terrorism officers are investigating three “small improvised explosive devices” believed capable of starting small fires that were found in separate locations in London on Tuesday. The suspicious packages containing padded envelopes were found at an office block next to Heathrow Airport, the post room at Waterloo station and at offices near London City Airport in the east of the capital, according to Scotland Yard. “The packages — all A4-sized white postal bags containing yellow Jiffy bags — have been assessed by specialist officers to be small impr...