Israel faced a widening conflict on Friday, as deadly violence erupted across the West Bank amid a massive aerial bombardment in Gaza and unprecedented unrest among Arabs and Jews inside the country.

The West Bank clashes, described as among the most intense since the second intifada that began in 2000, left 10 people dead from Israeli fire, the Palestinian health ministry said, as overall fatalities from strikes on Gaza rose to 122.

Hamas Islamists and other Palestinian armed groups in the enclave have launched more than 2,000 rockets at Israel since Monday, killing nine people, with air raid sirens wailing across the country throughout the week.

Israel's army said its overnight assault on Gaza involved fighter jets and tanks hitting a Hamas tunnel network dug under civilian areas.

Towers and homes were levelled, while rockets tore through the skies towards Israel.

Gazan families sought shelter at a school, fearing another barrage.

"All the children are afraid and we are afraid for the children," said Kamal al-Haddad, who fled with his family to a UN-supported school in Gaza City.

Umm Raed al-Baghdadi, who also fled her home, said Gazans "who have been in war since childhood... cannot bear it anymore".

The fighting in blockaded Gaza, the worst since a 2014 war, exploded following weeks on hostilities in east Jerusalem, the Israeli-annexed part of the city Palestinians claim as their capital.

Israeli soldiers have massed on Gaza's edge, but the army's overnight statement that a ground invasion had commenced proved false.

The Gaza death toll includes 31 children, and 900 were injured, authorities said, while the Israeli fatalities count one child and one soldier, with 564 injured. 

West Bank unrest 

Violence on Fridays in the West Bank is a traditional facet of the decades-old Israeli-Palestinian conflict, but the escalation across the territory appeared linked to the hostilities in Gaza and the internal Israeli unrest.

Thick black smoke from burning tyres billowed from a clash point on a main road leading into central Ramallah, where mainly young Palestinians hurled stones, Molotov cocktails and other projectiles. 

Israeli forces have responded with water canon spray, tear gas, rubber bullets and live rounds. 

The health ministry said more than 150 were injured across the territory occupied by Israel since 1967, as it appealed for blood donations.

A Palestinian security source said Friday's fighting was the "most intense" since the second intifada, or uprising, that began in 2000.

The UN said the Security Council would meet Sunday to address Gaza.

China accused the US of "ignoring the suffering" of Muslims, after Washington stopped the council from meeting Friday.

US Secretary for Israel-Palestinian Affairs Hady Amr has landed in Israel, as part of mediation efforts

The US State Department urged citizens to "reconsider" travel to the country.

German Chancellor Angela Merkel's spokesman said rocket fire by Hamas against Israel amounted to "terrorist attacks".

Several international airlines cancelled flights amid the onslaught.

'Not over yet'

Israel has hit roughly 750 sites it described as military targets such as Hamas bomb-making facilities and the homes of senior militant commanders. Several high-rise buildings were flattened.

Israel estimates that more than 30 leaders of Hamas and its ally Islamic Jihad have been killed.

"I said we'd deliver heavy blows to Hamas and other terror groups, and we're doing that," Prime Minister Benjamin Netanyahu said.

"They're paying and will continue to pay dearly for that. It's not over yet."

Three rockets were also fired late Thursday from southern Lebanon towards Israel, landing in the Mediterranean, the military said.

A source close to Israel's arch-enemy Hezbollah said the Lebanese Shiite group had no link to the incident.

The army said it "fired warning shots towards a number of rioters who crossed from Lebanon into Israeli territory" on Friday forcing them back into Lebanon. A 21-year-old man died from his injuries, according to Lebanese state media. 

'Lynching'

Within Israel, an unprecedented wave of mob violence has seen Arabs and Jews savagely beat each other and attack places of worship.

More than 750 people have been arrested this week, police said.

In Lod, where an Arab man was shot dead by a Jewish Israeli on Monday, the outside of a synagogue was burnt overnight, they added.

Officers had detained Jews "walking around looking for trouble" in Netanya and Beersheba, while Arabs in other towns attacked police and police stations with stones and petrol bombs.

Arab citizens of Israel, who comprise a fifth of the population, say they were enraged by Israeli police storming the Al-Aqsa mosque compound in Jerusalem, where officers were attacked by protesters throwing stones and other projectiles.

In one of the most shocking episodes of the intercommunal violence, a far-right Jewish mob beat a man they considered an Arab in Bat Yam, near Tel Aviv on Wednesday, leaving him with serious injuries.

Israel's civil aviation authority said it was directing incoming flights to Tel Aviv to circle offshore when rockets are being fired from Gaza, with pilots choosing whether to divert to Ramon airport in the south or wait until runways are checked for ordnance.