Violent clashes between Israeli troops and Palestinians have spread across much of the occupied West Bank, following days of hostility in Gaza.
At least 10 Palestinians are reported to have died in the West Bank unrest, while hundreds have been injured.
Israeli forces used teargas, rubber bullets and live fire, as Palestinians threw petrol bombs.
The confrontations in the West Bank mark a broadening out of some of the worst violence in the region in years.
The conflict began on Monday and followed weeks of spiralling Israeli-Palestinian tension in East Jerusalem. The increased hostilities culminated in clashes at a holy site revered by both Muslims and Jews. Hamas - the militant Islamist group which rules Gaza - began firing rockets after warning Israel to withdraw from the site, triggering retaliatory air strikes.
At least 126 people have been killed in Gaza and eight have died in Israel since the fighting began.
Many towns and cities in the occupied West Bank were convulsed by angry protests on Friday, prompting international calls for calm.
There were running battles between Israeli soldiers and young Palestinians, who appear newly emboldened by the events of the past week, the BBC's Arab affairs editor Sebastian Usher says.
Meanwhile, there were protests at the Jordanian and Lebanese borders with Israel, in support of the Palestinians, on Friday. One man died after being hit by Israeli shell fire while protesting, state media in Lebanon reported.
The Israeli military said it conducted an operation overnight to destroy a network of Hamas tunnels that it dubbed "the metro", but no troops had entered Gaza. It added that - over the course of Thursday evening and Friday morning - 220 more projectiles were fired from the Gaza Strip.
In southern Israel, an 87-year-old woman died after falling on her way to a bomb shelter near Ashdod. Other areas including Ashkelon, Beersheba and Yavne were also targeted.
Gaza's health ministry said 31 children were among those killed since fighting began, and many other civilians have died. Another 950 Gazans have also been wounded. Israel says dozens of those killed in Gaza were militants, and some of the deaths were caused by misfired rockets from Gaza.
On Friday, the United Nations said that an estimated 10,000 Palestinians had left their homes in Gaza since Monday because of the conflict.
The conflict has also seen Jewish and Israeli-Arab mobs fighting within Israel itself, prompting the president to warn of civil war. Defence Minister Benny Gantz ordered the security forces to suppress the internal unrest on Thursday, and more than 400 people were arrested.
Police say Israeli Arabs have been responsible for most of the trouble and have rejected the accusation that they are standing by while gangs of Jewish youths target Arab homes.
In Gaza, Palestinians fearing an incursion by Israeli troops have been fleeing areas close to the border with Israel. Residents who had left Shejaiya in Gaza City said shells had been falling on homes.
"We felt like we were in a horror movie," said local resident Salwa Al-Attar, who escaped the bombardment with her family. "The planes were above us, and the tanks and navy were bombing - and we could not move. The children, women and men were screaming."
In a statement released early on Friday morning, Israeli Prime Minister Benjamin Netanyahu said the military operation against Palestinian militants would continue for "as long as necessary". He added that Hamas would pay a heavy price, as would other "terrorist groups".
A Hamas military spokesman said the group was ready to teach Israel's military "harsh lessons" should it decide to go ahead with a ground incursion.
On Thursday, Israel's military called up 7,000 army reservists and deployed troops and tanks near its border with Gaza. It said a ground offensive into Gaza was one option being considered but a decision had yet to be made.
BBC
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