A week after Israel Prize laureate Professor Zeev Sternhell was the target of a bomb attack, fears are mounting that a new far-right Jewish underground cell has begun operations in the West Bank and is planning more attacks against left-wing personalities.
The group is suspected of carrying out a series of recent bomb attacks, including against a Messianic Jewish family in the settlement of Ariel in which a young boy was seriously wounded.
They are also suspected of assembling an explosive device to detonate during last year's Jerusalem Gay Pride parade. The bomb was discovered in the West Bank a week before the parade and destroyed by police sappers.
The investigation into the bombing is being conducted jointly by police and the Shin Bet security agency. As part of their inquiries, investigators are combing internet forums frequented by right-wing activists, in search of clues.
Mr Sternhell, a world-renowned historian, received Israel's highest award this year, drawing ire from right-wing groups which opposed the professor's left-wing and anti-settlement views. Last Thursday, a pipe bomb went off outside the 73-year-old's Jerusalem home. He was lightly injured and spent the night in a local hospital.
"This was obviously the work of the far right," Mr Sternhell said. "It could have been a lone lunatic, an organisation, a cell of three or a whole settlement which all decided to set the record straight with me."
The attack is one of the worst cases of political violence in Israel since Yigal Amir assassinated Prime Minister Yitzhak Rabin in 1995.
Mr Sternhell was born in Poland in 1935, fled the Holocaust to France and immigrated to Israel in 1951. An expert on the emergence of fascism, he teaches at Jerusalem's Hebrew University.
Investigators found flyers near his home offering an NIS 1.1m (£180,000) reward to anyone who kills a Peace Now activist. In response, police beefed up security surrounding Peace Now secretary-general Yariv Oppenheimer.
"There is an overall radicalisation among settlers," Mr Oppenheimer told the JC. "There are also Jewish terrorists and we fear that this is a new underground that plans to begin operating more frequently. We call on the government to stop allowing the settlers to do what they want, and this starts with building at the illegal outposts."
The attack against Mr Sternhell was condemned by politicians from across the political spectrum. Defence Minister Ehud Barak said it had brought Israel back to a "dark time" and that the defence establishment would do all it could to catch the culprits.
Public Security Minister Avi Dichter said the bombing was a "nationalistic terror attack" that was aimed at killing and not just intimidating Sternhell.