London counter-terror officers are being assisted by Irish police as investigations continue into three explosive devices sent to transport hubs.
The parcels were received on Tuesday at Waterloo Station, and at premises close to London's Heathrow and City Airports.
It's thought some of them were posted from Ireland.
Police say they retain an open mind about the motive behind the incidents which they are linking.
No one was injured by the devices, although one of them briefly ignited.
Former bomb disposal officer Lucy Lewis says it appears not to have been sophisticated.
IN: "It sounds...
OUT: ...opened it."
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