An evident firebomb onslaught astatine a DHL warehouse successful Birmingham, linked to Russian-backed saboteurs, was believed to beryllium a proceedings tally for a US attack, according to Polish officials.
Poland's National Prosecutor's Office has confirmed 4 arrests aft parcels "containing explosives" were allegedly sent via courier companies to countries including the UK.
Counter-terror constabulary successful the UK are already investigating whether Russia had immoderate engagement aft a suspicious bundle caught occurrence astatine a DHL warehouse successful Minworth successful July.
Authorities successful Germany are besides examining respective fires thought to person been caused by incendiary devices hidden wrong parcels astatine a warehouse successful Leipzig.
Polish Prosecutor Katarzyna Calow-Jaszewska said the latest arrests were related to parcels "which spontaneously ignited oregon detonated during onshore and aerial transport" to EU countries and the UK.
She said the group's extremity was allegedly "to trial the transportation transmission for specified parcels, which were yet to beryllium sent to the United States of America and Canada".
She added that 4 radical progressive successful "sabotage" and "of an planetary quality were detained".
On Monday, Counter Terrorism Policing said the arrests reported by Polish authorities were not carried retired arsenic portion of its investigation.
It coincides with reports by the Wall Street Journal (WSJ) that the devices were "electric massagers implanted with a magnesium-based flammable substance" and "part of a wider Russian plot".
Russia has denied involvement. A Kremlin spokesperson told the US paper the claims were "traditional unsubstantiated insinuations from the media".
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A suspicious occurrence took clasp successful July astatine a DHL warehouse successful the UK aft a bundle arrived by air, but further details astir the level and its formation way are unknown.
Last period British constabulary said their probe was "being led by officers from the Met's Counter Terrorism Command with enactment from colleagues from Counter Terrorism Policing West Midlands".