Duma West Bank arson attack
Mourners react next to the body of 18-month-old Ali Dawabsheh, who was killed after his family's house was set on fireReuters

Israel has approved the extension of the controversial system of administrative detention – which is usually applied to Palestinian militant suspects – to Jewish settlers in an attempt to hunt down those responsible for the killing of a Palestinian toddler in a West Bank arson attack.

The administrative detention allows Palestinians to be tried in secretive military tribunals with the prospect of being thrown in jail for months and even years without facing formal charges or trial. Israeli human rights group B'Tselem explains it "is not intended to punish the detainee for an offense that has been committed, but to prevent a future offence".

The application to Jewish ultra-nationalist settlers shows the right-wing government of Prime Minister Benjamin Netanyahu is under pressure to curb attacks by extremists, which have intensified in the occupied West Bank in the past year.

The arson at Duma village, near Nablus, killed an 18-month toddler and seriously injured his parents and brother. Though nobody claimed responsibility for the attack, graffiti scrawled on the walls reading "Long live the Messiah", "revenge", and "price tag" are compatible with the price-tag movement.

Netanyahu called the attack a terrorist act and vowed to catch the assailants. His security cabinet took the step to extend the administrative detention to Israelis as well "to take all steps necessary to bring those responsible to justice and prevent such attacks from occurring in the future", a statement said.

According to figures of the Israel Prison Service (IPS), 396 Palestinians from the West Bank, including one woman, are being held in administrative detention.