Israel launched its campaign five days ago to stop relentless rocket fire on its citizens. While there have been no fatalities in Israel, Gaza Health Ministry spokesman Ashraf al-Kidra said overnight attacks raised the death toll there to over 120, with more than 920 wounded.
Dozens of the dead are civilians, though the exact breakdown remains unclear.
Hamas said Israel for the first time also hit a pair of mosques in its offensive. It hopes the incident will galvanize support in the Muslim world.
''The bombing of two mosques in Gaza overnight shows how barbaric this enemy is and how much is it hostile to Islam,'' said Husam Badran, a Hamas spokesman in Doha, Qatar. ''This terrorism gives us the right to broaden our response to deter this occupier.''
The Israeli military released an aerial photo of the mosque it hit, saying it concealed rockets right next to another religious site and civilian homes. It said Hamas, Islamic Jihad and other Gaza militant groups systematically use this tactic of abusing religious sites to conceal weapons and establish underground tunnel networks, deliberately endangering its own civilians.
''Hamas terrorists systematically exploit and choose to put Palestinians in Gaza in harm's way and continue to locate their positions among civilian areas and mosques, proving once more their disregard for human life and holy sites,'' said Lt. Col. Peter Lerner, an Israeli military spokesman.
Gaza militants have fired nearly 700 rockets and mortars toward Israel in five days of fighting. The ''Iron Dome,'' a U.S.-funded, Israel-developed rocket defense system, has intercepted more than 130 incoming rockets, preventing any Israeli fatalities so far.
Israel's military says it has struck more than 1,100 targets, including rocket launchers, command centers and weapon manufacturing and storage facilities, delivering a devastating blow to the Islamic militants.
The offensive is the heaviest fighting since a similar eight-day campaign in November 2012 to stop Gaza rocket fire. The outbreak of violence follows the kidnappings and killings of three Israeli teenagers in the West Bank, and the kidnapping and killing of a Palestinian teenager in an apparent revenge attack.
Israel has pummeled Gaza at twice the rate of the 2012 operation and Israeli Prime Minister Benjamin Netanyahu has vowed to press on with the campaign until there is a complete halt to rocket attacks from the seaside Palestinian territory. Israel has massed thousands of troops along the border in preparation for a possible ground invasion.
After days of little criticism, Israel has begun coming under more international pressure as Palestinian casualties have grown.
A senior Arab league official said Arab foreign ministers will hold an emergency meeting in Cairo on Monday to discuss the continued Israeli offensive and measures to urge the international community to pressure Israel.
Palestinian President Mahmoud Abbas requested the meeting, which was approved by several Arab foreign ministers in coordination with the Arab League. The official spoke on condition of anonymity because he was not authorized to brief journalists.
Meanwhile, the Palestinians and their international supporters are discussing a United Nations draft resolution that would condemn all violence against civilians in the Israeli-Palestinian conflict and call for ''an immediate, durable and fully respected cease-fire.'' However, the Palestinian draft makes no mention of the firing of hundreds of rockets into Israel by Hamas, likely making it unacceptable to the United States if it was introduced in the U.N. Security Council.