Mosque Set on Fire in Northern Israel
The attack followed a series of similar assaults on mosques in the West Bank by arsonists suspected of being radical settlers as part of a campaign known as “price tag,” which seeks to exact a price from local Palestinians for violence against settlers or from Israeli security forces for taking action against illegal construction in Jewish outposts in the West Bank.
When they are "radical settlers"
Or from the LA Times:
REPORTING FROM JERUSALEM -- Jewish extremists are suspected of torching a mosque in a northern Israeli town early Monday, the latest in a string of anti-Arab attacks that have enraged Palestinians and alarmed Israeli security officials.
note: The LA Times said that the extremists had created "terror cells" and that the action was an "act of terrorism" but still did not call the persons who did the act "terrorists".