Who could be behind hoax bomb threats to European air travel?

Several European airlines and airports received coordinated bomb threats, most of which were treated as credible and led to aircraft diversions; Italian fighter jets were also scrambled to escort a plane. The threats were all false, but authorities must still take future warnings seriously, disrupting air travel and raising security concerns.

Some have suspected Russian involvement because of other recent hostile or suspicious incidents across Europe, and Russian commentators have voiced support for causing disruption in Western countries. However, as of Thursday evening, there was no hard evidence linking the threats to Russia, Iran or their proxy groups. An email to Rome airport authorities used the name of a banned Russian ultra-right group, but it may have been sent by someone impersonating it; investigators are looking for verifiable leads.