- "Stop the fire immediately. We're escalating towards a full scale war," Tor Wennesland, United Nations Middle East envoy, said via Twitter.
- The dramatic escalation of tensions follows protests over the potential eviction of Palestinian families from east Jerusalem by Israel's Supreme Court and access to one of the most sacred sites in the city.
The United Nations has called for an immediate cease-fire between Israel and Palestinians, warning that the devastating violence is on the cusp of spiraling out of control.
The most severe outbreak of violence between Israel and the Palestinians since the 2014 war in Gaza has prompted a deepening sense of international concern, with ostensibly no end in sight to the crisis.
Get San Diego local news, weather forecasts, sports and lifestyle stories to your inbox. Sign up for NBC San Diego newsletters.
"Stop the fire immediately. We're escalating towards a full scale war," Tor Wennesland, United Nations Middle East envoy, said via Twitter late Tuesday.
"Leaders on all sides have to take the responsibility of deescalation. The cost of war in Gaza is devastating & is being paid by ordinary people. UN is working (with) all sides to restore calm. Stop the violence now."
The Palestinian extremist group Hamas, which rules in Gaza has been firing hundreds of rockets on Israel, including at Tel Aviv and Jerusalem, and Israel retaliated with deadly airstrikes on Gaza. The enclave is where roughly 2 million Palestinians have lived under a stringent Israeli-Egyptian blockade since Hamas came to power in 2007.
Gaza's Health Ministry said Wednesday the death toll from Israeli airstrikes had climbed to 43 Palestinians, including 13 children. Israeli airstrikes also leveled two tower blocks on Tuesday.
The United Nations cited reports on Tuesday that more than 900 Palestinians in east Jerusalem had been injured between May 7 and May 10, and over 200 in the West Bank, "most by Israeli security forces," some of whom had also been hurt.
More than 1,000 rockets have been fired by Palestinian militants at Israeli towns in the past 36 hours, according to Israel's Foreign Ministry. Five people have been killed by rocket fire, Israel said, with over 200 injured.
Israeli Prime Minister Benjamin Netanyahu said earlier this week that Hamas had crossed a "red line" by firing rockets on the Jerusalem area for the first time since 2014.
On Tuesday, Hamas said it had launched "a massive rocket strike against Tel Aviv and its suburbs, with 130 rockets, in response to the enemy's targeting of residential towers," according to Reuters.
Israel Defense Forces said people in Tel Aviv, the country's second-most populated city, were being rushed to bomb shelters early Wednesday. A barrage of rocket fire also prompted all flights to be halted to Tel Aviv's Ben Gurion Airport.
The dramatic escalation of tensions follows protests over the potential eviction of Palestinian families from a neighborhood in east Jerusalem by Israel's Supreme Court and access to one of the most sacred sites in the city. The court was to hold a hearing on Monday on the deeply contentious eviction case brought by right-wing Israelis but delayed an announcement because of rising tensions coinciding with the anniversary celebration of Israel's recapture of Jerusalem in the 1967 war and the Muslim observance of Ramadan.
The United Nations agency responsible for Palestinian refugees, UNRWA, sounded the alarm on Monday that over eight Sheikh Jarrah families, approximately 75 persons in total, were at risk of forced eviction.
Violent clashes between Israeli security forces and Palestinians were also reported on Friday as Muslims were reportedly blocked from reaching Al-Aqsa Mosque, Islam's third-holiest site.
Rupert Colville, a U.N. rights office spokesperson, said the treatment of those protesting and even those who weren't protesting last week was "extremely worrying."
"People who were simply praying or people who were having their iftar, who've been subjected to violence or completely unprovoked responses by the security forces," Colville said, referring to the evening meal that breaks the daytime fast during the month of Ramadan.
U.S. Secretary of State Antony Blinken said via Twitter on Wednesday that he had spoken about the escalating violence with Israeli Foreign Minister Gabi Ashkenazi.
"Israelis and Palestinians need to be able to live in safety and security, as well as enjoy equal measures of freedom, security, prosperity, and democracy," Blinken said.
— CNBC's Marty Steinberg contributed to this report.