Pakistan, Nov. 7 -- Newsrooms in Ireland and Bulgaria received emailed bomb threats on Friday from a purported "Mikhail Andropov", claiming responsibility for a widening wave of hoax threats disrupting passenger flights across Europe.

The messages, sent to Bulgaria's Nova TV and the Irish public broadcaster RTE, which evacuated its offices and suspended programming, were headlined "Message to the West" and portrayed the threats as the prelude to a series of attacks on means of transport across Europe. The British broadcaster Sky also said it had received a security threat.

Reuters was not able to establish the identity of the sender, the origin of the emails, or whether they had in fact come from the same source as the threats to any or...