"While Israel has the right to protect its civilian population, everything must be done to prevent a broader conflict, which would, first and foremost, affect the civilian populations on both sides and result in further casualties and more suffering," a spokesman for EU's foreign policy chief Josep Borrell said in a statement.

Israel hit Gaza with deadly air strikes since Friday, killing at least 14 people and injured 110. Palestinian militant group Islamic Jihad retaliated with a barrage of rocket fire.

In another development, Russia called on all sides to exercise maximum restraint while Pakistani Prime Minister Shahbaz Sharif condemned the Israeli air strike in Gaza. The United Nations, along with Egypt and Qatar, are stepping up mediation efforts to end the fighting.