Israel intensified attack on Gaza as Hamas continued to fire rockets into Israel on the fifth day of hostilities.
Israel’s military said air and ground forces were involved in attacks on Friday but had not entered Gaza.
Meanwhile, clashes between Palestinians and the Israeli security forces spread across much of the occupied West Bank.
At least 122 people have been killed in Gaza and eight have died in Israel since the fighting began on Monday.
Jewish and Israeli-Arab mobs have also been fighting within Israel, prompting its president to warn of civil war.
Defence Minister Benny Gantz ordered a “massive reinforcement” of security forces to suppress the internal unrest that has seen more than 400 people arrested.
Police say Israeli Arabs have been responsible for most of the trouble and reject the accusation that they are standing by while gangs of Jewish youths target Arab homes.
This week’s violence in Gaza and Israel is the worst since 2014. The fighting between Israel and Hamas was triggered by days of escalating clashes between Palestinians and Israeli police at a holy hilltop compound in East Jerusalem. Palestinians are also angry over eviction of Palestinian families by Jewish settlers.
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.
The Israeli military said it had conducted an operation overnight to destroy a network of Hamas tunnels that it dubbed “the metro”, but no troops had entered Gaza.
Gaza’s health ministry said 27 children were among those who’ve been killed since fighting began, and many other civilians have died. Another 600 Gazans have also been wounded.
In a statement released early on Friday morning, Israeli PM Benjamin Netanyahu said the country’s 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.