WARSAW (Reuters) - Russian intelligence services were likely behind a series of parcels that exploded in courier depots across Europe, Polish prosecutors said on Friday, pointing the finger at Moscow in a case officials say could have caused an air disaster.
Western officials have previously said that Russia has tried to destabilise allies of Ukraine with acts of sabotage. The explosions in courier depots in Britain, Germany and Poland in July had the potential to mark a serious escalation by causing an explosion on an aircraft.
Security officials have said that the parcels were part of a plot that ultimately aimed to trigger explosions on cargo flights to the United States and Canada.
"The evidence collected in the case indicates a high probability that the discussed acts of sabotage... were inspired by Russian special services," Polish Prosecutor's Office spokesperson Przemyslaw Nowak said in an emailed statement.
The Russian embassy in Warsaw did not immediately respond to an emailed request for comment. Russia has previously denied involvement.
Nowak said Polish authorities are searching for two Russians and have detained four Ukrainian citizens as part of the investigation.
Polish prosecutors said in October they had detained four people and were searching for two others in relation to the packages, but did not reveal the nationalities of those accused of involvement.
In October prosecutors said they were investigating the role of "foreign intelligence", without explicitly naming Russia.
"Intensive activities are being carried out to identify the remaining individuals involved in the above international group," Nowak said in the statement sent on Friday.
"These actions are undertaken in cooperation with law enforcement agencies of other European Union countries."
He said that the exploding parcels had been sent from the Lithuanian capital Vilnius.