A 13-year-old boy and a girl aged about 10 were among those injured by the shelling on Tuesday, which the Israeli military said was aimed at a source of mortar fire on the illegal Gush Khatif settlement.
The shelling was carried out by troops manning a post near the illegal Neve Dekalim colony and came several hours after a failed Israeli air strike on a car carrying two Palestinian resistance fighters in the same area.
The car was targeted by a drone that fired a single rocket in the Khan Yunus region of the southern Gaza Strip, witnesses said.
Palestinian security sources said both men who fled the strike on foot were members of the Islamic Jihad movement that seeks to push Israeli occupation forces out of Gaza and the West Bank by force of arms.
Israeli security sources confirmed the strike, saying their target had been resistance members behind the firing of mortars which have become increasingly frequent in recent days.