ISIS is now seeking the release of a former suicide bomber in exchange for Kenji Goto's freedom.
The latest carnage in the eastern Ukrainian city has prompted the West to ratchet up pressure on Russia.
A group sympathetic to ISIS' cause claimed responsibility for the online attack.
With 60 percent of the vote counted, Syriza won 149 seats in the 300-seat Greek parliament.
The plot would avenge the death of an Iranian general killed in a presumed Israeli airstrike.
The Northeast could face a crippling blizzard, thanks to winter snowstorm Juno.
Nigerian forces battled Boko Haram militants in clashes that killed 200 combatants.