A four-year-old child was one of two people killed by Israeli tank fire in Gaza on Monday, medics said, hiking the Palestinian death toll from Israel's 21-day operation to 1,037.

According to emergency services spokesman Ashraf al-Qudra, four-year-old Samih Ijneid was killed when a shell hit a house to the east of Jabaliya where clashes had recently erupted between Israeli troops and Hamas militants.

The shelling also killed a second person in the same area, he said.

The deadly shelling came as both sides observed an unofficial lull in the fighting as Muslims began marking the first day of the Eid al-Fitr holiday.

Earlier on Monday, another three people succumbed to their injuries, raising the day's toll to five, Qudra said.

More than 6,200 Palestinians have been injured in the ongoing violence which began with an intensive air campaign on July 8 and expanded when Israel sent ground troops into the Gaza periphery on July 17.

Figures released Sunday by the UN humanitarian agency OCHA give a figure of 999 dead, including at least 760 civilians, among them 226 children.

Of the 6,233 injured, 1,949 were children, it said.

OCHA also said 215,000 Palestinians had been internally displaced by the ongoing fighting, with the UN agency for refugees saying 170,461 of them had taken refuge in 82 of its shelters. The rest were staying with relatives or friends.

The conflict has also cost the lives of 43 Israeli soldiers, all of whom were killed since the ground operation began, as well as two civilians and a Thai agricultural worker who were killed by rocket fire.

Since Israel began Operation Protective Edge on July 8, the army says it has attacked 3,870 targets in Gaza, and militants have fired approximately 2,000 rockets which hit Israel, with around 500 shot down by its missile defence system, Iron Dome.

Since midnight (2100 GMT), only one rocket has struck Israel, hitting the southern city of Ashkelon without causing injury or damage, a military spokeswoman said.