Russia could be plotting to plant bombs on passenger and cargo jets heading to the US, security officials in Europe say.
Incendiary devices found being shipped across Europe could be a test for a covert Russian operation to start fires on planes flying to the States.
Investigators have discovered at least two such devices after fires at DHL shipping hubs in Leipzig, Germany and Birmingham, Britain.
Poland’s national prosecutor’s office said four people had been arrested in connection with the fires.
They have been charged with participating in sabotage or terrorist operations on behalf a foreign intelligence agency.
“The group’s goal was also to test the transfer channel for such parcels, which were ultimately to be sent to the United States of America and Canada,” the prosecutor’s office said.
It made no reference to which foreign government was behind the covert operations. However, Pawel Szota, the head of Poland’s foreign intelligence agency, said Russia was to blame.
The secretive weapons were found to be electronic massagers modified with a flammable magnesium-based substance, according to a report by the Wall Street Journal.
Evading security
Western sources have previously told The Telegraph that these items are being shipped to Germany and Britain from Poland and Lithuania.
One source said these incendiary devices do not get caught by traditional security controls carried out by air freight firms before they load up their plans with cargo.
He said this was a major escalation in Moscow’s hybrid war against Nato allies, adding: “I’m not sure the political leaders of Russia are aware of the consequences if one of these packages exploded, causing a mass casualty event.”
Konstantin von Notz, head of the intelligence oversight committee in the German parliament, said that he “expects all security authorities and the judiciary to work flat out to fully clarify the background” to the suspected sabotage at Leipzig..
The head of Germany’s domestic spy agency said that it was a “lucky coincidence” that no one was hurt when a package caught fire at the logistics centre in July.
Speaking in front of the German parliament, spy boss Thomas Haldenwang said that the suspect packet would have caused a plane crash had it detonated during a flight. “Debris could have hit people in Germany who openly sympathise with Putin,” he said, describing the packages as “a great danger”.
Germany’s federal prosecutors have also opened an investigation into the explosion.
Western officials have repeatedly warned of a mounting threat posed by Russia, a campaign seen as an attempt to deter support for Ukraine.
There have been multiple reports of mysterious fires at businesses linked to the West’s backing for Ukraine’s fight against the Russian invasion.
Intelligence sources have expressed fears that Russian intelligence operations could soon be aimed at US military bases in Europe.
The threat normally increases at times when decisions are being made over bolstered support for Ukraine, such as discussions over whether Kyiv should be permitted to fire Western missiles inside Russia.
A US Government official said it saw “no current active threat targeting US-bound flights”.
The official told The Telegraph: “We continue to be vigilant against threats to aviation and air cargo systems. We work closely with industry to take steps to protect potential threats whenever they emerge.”
A Transportation Security Administration spokeswoman said: “Over the past several months, as part of a multi-layered security approach, TSA worked with industry partners to put additional security measures for US aircraft operators and foreign air carriers regarding certain cargo shipments bound for the United States.”
The Kremlin denied it was to blame for the alleged acts of sabotage.