Several suspected Jewish militants, detained for questioning by Israeli police on Sunday, have been released.
At least seven were detained amid a crackdown on Jewish extremists in the wake of a deadly arson attack in the West Bank, which Palestinians have blamed on Jewish settlers.
The injured father of the family whose home was firebombed died on Saturday. His 18-month-old son died on 31 July.
There have been no arrests yet in direct connection with the attack.
Toddler Ali Saad Dawabsha died on the day of the firebombing, in the West Bank village of Duma.
His mother and four-year-old brother remain in critical condition.
Ali’s father, Saad, 32, died in an Israeli hospital where he was being treated for second-degree burns to most of his body.
The suspected extremists were held in raids on settler outposts – wildcat settlements not authorised by the government – in the West Bank.
Separately, Israel has put three alleged Jewish militants in a controversial form of detention without trial since the crackdown began after the Duma attack.
Administrative detention – a measure usually affecting Palestinians – allows suspects to be held without charge for six-month intervals and can be renewed indefinitely.
The Dawabsha family’s home was one of two houses set on fire and daubed with slogans in Hebrew, including the word “revenge”.
Palestinians have accused Jewish settlers of carrying out the attack; Israel has not said whether it holds settlers responsible, and an investigation is ongoing.
Israeli Prime Minister Benjamin Netanyahu called the attack an act of terrorism and has said every effort will be made to catch the culprits.
The incident is reminiscent of so-called “price tag” attacks.
Such attacks usually involve acts of vandalism or arson by Jewish militants as retribution for actions taken by the Israeli government against settlements or unauthorised outposts in the West Bank, or for violence by Palestinians.
Palestinians regard settlements as a major obstacle to building a sought-after state in contiguous territory in the West Bank and East Jerusalem, and tensions between the two communities are often high.
About 500,000 Jews live in more than 100 settlements built since Israel’s 1967 occupation of the West Bank and East Jerusalem. The settlements are considered illegal under international law, though Israel disputes this.