Palestinian locals in Gaza Strip woke up Thursday to celebrate Eid al-Fitr, one of the most sacred occasions in the Islamic calendar in the wake of deadly Israeli airstrikes.

Heavy bombardment continued early in the day as Israel's military launched a streak of airstrikes on various locations in Gaza Strip in response to the 130 rockets Hamas unleashed on Israeli cities on Wednesday, Aljazeera reported.

Violence between Israelis and Palestinians entered its fourth day and casualties climbed on both sides. Sirens blared through the night across Israel with at least one rocket hitting a suburb of Tel Aviv, causing significant damage and injuries, Israeli officials said.

The worst fighting in years between Israelis and Palestinians showed no signs of abating, prompting the United Nations to issue a warning the conflict could spiral out of control and turn into a "full-scale war," CNN said.

The violence broke out Monday following weeks of escalating Israeli-Palestinian tension in East Jerusalem which culminated in clashes at a holy site revered by Jews and Muslims.

"Nothing can justify an Arab mob assaulting Jews, and nothing can justify a Jewish mob assaulting Arabs," The Times of Israel quoted Israeli Prime Minister Benjamin Netanyahu as saying in a video statement.

In Gaza, residents awoke to thick smoke billowing from areas bombed by Israeli military forces, which said it had carried out overnight operations against the militant group Hamas, which controls Gaza.

According to Gaza's Health Ministry, the death toll climbed to 69 Palestinians, including 16 children, the Associated Press reported.

Hamas confirmed that Bassem Issa, its Gaza City commander, was killed in an Israeli airstrike along with other top members of the group. The national security office of Hamas was also reportedly struck again by Israeli jets early Thursday.

Meanwhile, Palestinian Authority Prime Minister Mohammad Shtayyeh slammed the UN Security Council for its failure to release a joint statement on the worsening situation following a second meeting on Wednesday.

"Failure to condemn Israel in the U.N. gives it the green light to commit more crimes," he said on Twitter.