The use of "administrative detention", which has previously been applied to Palestinians, came as authorities yesterday arrested another suspected Jewish extremist and extended the detention of the leader of a radical religious group.
None of the three were accused of direct involvement in last week's firebombing of a Palestinian home in the occupied West Bank in which an 18-month-old boy was killed, sparking an international outcry over Israel's failure to get to grips with violence by hardline Jewish settlers.
Yesterday, Defence Minister Moshe Yaalon signed an administrative detention order against Mordechai Mayer, an Israeli settler arrested for "his involvement in violent activities and terrorist attacks in recent times", a defence ministry statement said.
Media reports had suggested the attorney general had given permission for the authorities to take such action against three suspected extremists.
Israel normally applies administrative detention, which dates from British-mandated Palestine, against Palestinians, allowing them to be held without trial for renewable six-month periods.
Currently, 379 of the 5,686 Palestinian prisoners held in Israeli jail are on administrative detention, according to official figures, and a long list of Palestinian prisoners have gone on hunger strike to protest against the policy.
On Monday, meanwhile, authorities detained Meir Ettinger, whose grandfather Meir Kahane founded the racist anti-Arab Kach group, and a court prolonged his detention until the weekend on suspicion of "nationalist crimes".
Ettinger was arrested "because of his activities in a Jewish extremist organisation", a spokesman for the Shin Bet domestic security agency said.
According to Israeli media, he was the brains behind a June 18 arson attack on a shrine in northern Israel where Christians believe Jesus performed the miracle of the loaves and fishes.
The hearing was held in private.
