Prime Minister Benjamin Netanyahu pledged "a fight to the death against Palestinian terror" as clashes spread after two deadly attacks, while Jerusalem's Old City was closed to Palestinians for a second day Monday.
The Israeli premier's comments late on Sunday came as he convened security chiefs immediately after landing back from the United States to discuss the clashes in east Jerusalem and the West Bank.
Palestinian youths throwing stones and firebombs have faced off against Israeli security forces using both live rounds and rubber bullets. Jewish settlers have also clashed with Palestinians.
The rioting has followed three attacks in recent days that have killed four Israelis and wounded several others, including a two-year-old child.
Threatening to further stoke the flames, Israeli troops shot dead an 18-year-old Palestinian during clashes in Tulkarem in the West Bank on Sunday, Palestinian police and medics said. Dozens of others have been wounded.
There have been fears that the sporadic violence could spin out of control, with some warning of the risk of a third Palestinian intifada, or uprising.
Netanyahu, facing pressure from right-wing members of his governing coalition to respond forcefully, announced a package of new measures "to prevent terror and deter and punish the attackers".
They included swifter demolition of the homes of those accused of attacks, broader use of detention without trial for suspects, and police and troop reinforcements for Jerusalem and the West Bank.
He also spoke of using restraining orders to keep "inciters" away from the flashpoint Al-Aqsa mosque compound, the site of repeated clashes in recent weeks.
Palestinian president Mahmud Abbas, who said in a UN speech last week that he was no longer bound by previous accords with Israel, accused the Israeli government of escalating tensions.
It was not clear what Abbas's UN declaration would mean in practice, including whether he would act to end security cooperation with Israel.
Early on Monday, Israel carried out an air strike on the Gaza Strip in response to a Palestinian rocket attack from the territory, an army statement said. No casualties were reported from either side.
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The Gaza Strip is run by Abbas's rival, Islamist movement Hamas.
- Old City ban -
In a rare and drastic move, Israel barred Palestinians from Jerusalem's Old City on Sunday as violence spread after two Israelis were stabbed to death. The neighbourhood remained mainly quiet early Monday, with hundreds of police on patrol.
The Old City restrictions are to be in place through Monday, when Jews wrap up celebrations of the eight-day Sukkot holiday. Only Israelis, tourists, residents of the area, business owners and students were allowed in.
Worship at the sensitive Al-Aqsa mosque compound has been limited to men aged 50 and above. There were no age restrictions on women.
Around 300,000 Palestinians live in Israeli-annexed east Jerusalem, where the Old City is located.
Israeli security forces were already on alert after recent clashes at the compound and surrounding Old City, as well as the murder in the West Bank of a Jewish settler couple in front of their young children on Thursday.
On Saturday night, a 19-year-old Palestinian said to be an Islamist militant killed two Israelis in the Old City and wounded a child, prompting a further security clampdown.
The attacker first used a knife, but reportedly took a gun from one of the male victims and fired at police running to the scene, before he was himself shot dead.
Clashes broke out near the attacker's home outside Ramallah overnight Sunday to Monday when Israeli soldiers arrived, with residents fearing the house was to be demolished.
In a separate incident early Sunday, a 19-year-old Palestinian stabbed and wounded a 15-year-old passerby in west Jerusalem before being shot dead by police while fleeing.
Video circulated on social media showed what appeared to be the alleged attacker walking as bystanders shouted "shoot him" in Hebrew before a policeman fired and he fell to the ground.
Unrest later broke out in the Issawiya neighbourhood of east Jerusalem, where the attacker in Sunday morning's stabbing was from.