Israeli police have rounded up extremist Jewish settlers in their biggest operation in years.

The Shin Bet arrested nine people suspected of extremist activities against Palestinians on Sunday. Two more were placed in “administrative detention” without trial .

The raids – in the settlements of Adei Ad and Baladim – came after an increased police effort following an arson attack in Douma over a week ago which killed a Palestinian toddler and his father and triggered a number of violent attacks on the West Bank.

Prime Minister Benjamin Netanyahu said after the attacks that he was determined to crack down on “terror” and extended the process of administrative detention – the arrest of Palestinian extremists without trial – to violent Jewish ultra-nationalists.

“I promised we would use all the tools at our disposal to apprehend the murderers and deal with them to the fullest extent of the law, and this is what we are doing,” Mr Netanyahu said.

Three other Jews were arrested last week – Meir Ettinger, the so-called “most wanted” strictly Orthodox extremist; Eviatar Slonim and Mordechai Meyer.