In the latest bloodshed, an Israeli missile struck a motorcycle east of the south Gaza city of Khan Yunis, killing 17-year-old Ziyad al-Najjar, emergency services spokesman Ashraf al-Qudra said.

His death came shortly after another strike in the same area, which killed a 37-year-old who was standing with a group of men, Qudra said.

A 60-year-old man was killed in a raid on a house in Deir al-Balah in central Gaza, and two other people died in separate strikes elsewhere in the coastal enclave, he said in a statement.

Earlier, a man and a woman wounded in air strikes on Sunday died of their injuries, Qudra said, raising to seven the number of lives lost on Monday as a result of the air campaign.

So far, more than 1,280 have been wounded.

The Gaza-based Palestinian Centre for Human Rights (PCHR) said on Sunday that more than three-quarters of the victims were civilians.

The UN agency for Palestinian refugees (UNRWA) has said more than a quarter of them were children.

"All indications are, and I find this particularly dramatic, that women and children make up a sizable number of the victims of the current strikes. Currently more than one quarter of the fatalities are children," UNRWA Commissioner General Pierre Krahenbuhl said on Monday.

The bloodiest day so far was Saturday when 56 people were martyred in a series of deadly strikes, Qudra said.

No Israelis have been killed. Three have been seriously wounded since the start of the operation.

Israel began Operation Protective Edge before dawn on Tuesday in an attempt to halt cross-border rocket fire by Hamas resistance group.

Since then, more than 800 rockets have hit occupied lands, while some 187 others have been intercepted by its Iron Dome air defense system, the army said.

NJF/NJF