Israel bombed what it claimed were underground tunnels used by Hamas and Palestinian militants fired rocket barrages at Israeli cities as fighting spilled into a second week on Monday amid mounting international calls for a ceasefire.
There was no sign of any imminent end to the most serious hostilities in years between the two sides.
The sound of explosions roared overnight as dozens of Israeli fighter jets bombed what the military said was an underground tunnel system used by Hamas. Witnesses said roads, security buildings and militant training camps had been attacked in and around Gaza City, Reuters reported.
After Gaza rockets were fired at the Israeli cities of Beersheba and Ashkelon, Israeli aircraft struck nine residences belonging to high-ranking Hamas commanders, the military said. Some of the homes were used for weapons storage, it said.
Later in the morning, Palestinian media reported that Israel had struck a factory in northern Gaza. Video on social media showed a column of thick black smoke rising into the air.
There were no reports of casualties on either side of the border.
World concern had already deepened after an Israeli air strike in Gaza that destroyed several homes on Sunday and which Palestinian health officials said killed 42 people, including 10 children, and persistent rocket attacks on Israeli towns.
Injecting more urgency into Washington's calls for calm, US Secretary of State Antony Blinken wrote on Twitter: "All parties need to deescalate tensions - the violence must end immediately", after he spoke with Egypt's foreign minister about ongoing violence in Israel, Gaza and the occupied West Bank.
At a UN Security Council meeting on Sunday, the United States said it had made clear to Israel, the Palestinians and others that it was ready to offer support "should the parties seek a ceasefire". read more
Prime Minister Benjamin Netanyahu said Israel's campaign in Gaza was continuing at "full force", and that deterrence had to be achieved to prevent future conflict with Hamas.
"We are acting now, for as long as necessary, to restore calm and quiet to you, Israel's citizens. It will take time," Netanyahu said in a televised address after his security Cabinet met on Sunday.
The Gaza Health Ministry put the death toll since the hostilities flared at 197, including 58 children and 34 women. Ten people have been killed in Israel, including two children, Israeli authorities say.
Hamas began its rocket assault last Monday after weeks of tensions over a court case to evict several Palestinian families in East Jerusalem, and in retaliation for Israeli police clashes with Palestinians near the city's Al-Aqsa Mosque, Islam's third holiest site, during the Muslim holy month of Ramadan.
