Israeli forces have arrested a brother and an uncle of a Palestinian man accused of killing two soldiers in a West Bank car ramming late on Friday, the army said.
The alleged driver of the vehicle -- identified as Alaa Kabha, born in 1991 -- was already in custody having been detained injured at the scene and taken to hospital under guard.
Friday's car ramming, close to the Jewish settlement of Mevo Dotan near Jenin in the north of the occupied West Bank, also wounded two soldiers, one of them seriously.
Tensions were high after Palestinian Islamist movement Hamas called for a day of rage on Friday to commemorate 100 days since US President Donald Trump's controversial recognition of Jerusalem as Israel's capital.
Palestinians too see the city as their capital and Trump's recognition broke with decades of US policy that the its status would be negotiated between the parties.
At least 31 Palestinians and four Israelis have been killed since Trump's announcement, which set off major protests.
Hamas praised the attack but did not claim responsibility for it.
According to Israel's Shin Bet domestic security agency, Kabha had previously been interned for security reasons but was released in April last year.
Israeli soldiers inspected his family home following Friday's attack in readiness to demolish it.
Prime Minister Benjamin Netanyahu, in a statement on Saturday, said Israel will take tough action against Kabha.
"We will work to demolish the home of the terrorist and will deal with him to the fullest extent of the law," he said.
Israel routinely demolishes the homes of Palestinians who carry out attacks
Authorities also rescinded the permits of 67 of members of his extended family to work in Israel and those of 26 to do business with it.
Human rights groups condemn such measures as collective punishment but Netanyahu's right-wing government says they are a deterrent to attacks on Israelis.
Car rammings are a tactic that has been used repeatedly in a wave of lone wolf attacks that has hit Israel and the Palestinian territories since October 2015.
The frequency of such attacks had abated but has picked up again since Trump's Jerusalem announcement.