Ze'ev Sternhell, a political science professor at Hebrew University, had received telephone threats for some time and police told Ynetnews.com they believe the bombing was linked to the threats and based on ideological differences.

Police said fliers found in the streets near Sternhell's home promised a reward of $325,000 to anyone who kills a member of Peace Now, left-wing non-governmental organization. it wasn't clear whether Sternhell was a member of Peace Now.

Police assigned a security detail to Peace Now Secretary-General Yariv Oppenheimer, who said, "The extremist right poses an existential danger to Israeli democracy."

Israeli Defense Minister Ehud Barak said the country was "returning to the sinister phenomenon of using bombs against people, in this case against a very capable man who has never been afraid to voice his opinion, because his position ... is that of a liberal voice, a democratic voice, a sane voice amidst the incitement."

Barak said law enforcement officials "will not allow anyone from any dank corner of Israeli society to persecute anyone else."