Gaza militants fired new barrages of rockets at Israel on Sunday in a deadly escalation that has seen Israel respond with waves of strikes as a fragile truce again faltered, sparking fears of further violence.
Gazan authorities reported six Palestinians killed in Israeli strikes in the latest round of fighting that began Saturday, including at least two militants.
But Israel disputed their account of the deaths of a pregnant mother and her baby, blaming errant Hamas fire.
One 58-year-old Israeli man was killed overnight by a rocket strike on the city of Ashkelon near the Gaza border, Israeli police and the hospital said.
The latest flare-up came as Hamas, the Islamist movement that rules the blockaded Gaza Strip, sought further concessions from Israel under a fragile months-old ceasefire.
Israel said 450 rockets or mortars had been fired by Hamas and Islamic Jihad since Saturday and its air defences intercepted more than 150 of them.
As well as the Israeli man killed, an 80-year-old woman was seriously injured in a rocket strike on the Israeli city of Kiryat Gat, police and medics said.
A man was also hospitalised in Ashkelon, said police, citing other injuries without providing details.
A house near Ashkelon was damaged, while other rockets hit open areas.
The Israeli army said its tanks and planes hit some 220 militant targets in Gaza in response.
They included an Islamic Jihad attack tunnel that stretched from southern Gaza into Israeli territory, it said.
Two multi-storey buildings in Gaza City were also destroyed.
Israel said one of the buildings included Hamas military intelligence and security offices.
Turkey said its state news agency Anadolu had an office in the building, and strongly denounced the strike.
Israel said the other building housed Hamas and Islamic Jihad offices.
The Gaza health ministry said Israeli strikes killed a 14-month-old baby and her pregnant mother, 37, as well as four Palestinian men.
But Israeli army spokesman Jonathan Conricus said that based on intelligence “we are now confident” that the deaths of the mother and baby were not due to an Israeli strike.
“Their unfortunate death was not a result of (Israeli) weaponry but a Hamas rocket that was fired and exploded not where it was supposed to,” he said.
Islamic Jihad identified two of the dead men as its militants. The ministry said 47 other people were also wounded.
As the exchange of fire continued, Israeli Prime Minister Benjamin Netanyahu held consultations with security chiefs on Saturday. Cabinet was set to hold its normal weekly meeting on Sunday.