At least four Palestinians were killed when Israeli tanks shelled a UN-run school in Beit Lahya in northern Gaza Strip on Saturday morning, local medical sources and witnesses said.

Gaza emergency chief Mo'aweya Hassanein said that the tank shelling killed at least four and wounded ten, adding that three people were killed in northern Gaza City in an airstrike this morning.

Hassanein said the death toll since the beginning of the Israeli offensive on Gaza has risen to 1190, with an addition of 5200 wounded.

The Israeli army continued its ground operations and airstrikes on Saturday all across the Gaza Strip as its air and ground military offensive goes on for the 22th successive day.

Residents in the Gaza City said they can hear sound of bombing and shelling from east and west Gaza City, and also fightings between the Palestinian militants and the Israeli soldiers from the northern Gaza Strip.

Meanwhile, Islamic Hamas movement's armed wing al-Qassam Brigades claimed responsibility for three Grad rockets launched to the Southern Israel on Saturday.