kibuttz of Nahal Oz, on the border with the Gaza Strip. [AFP/David Buimovitch]
Gaza medical official Adham Abu Salmiya said the boy was injured in his chest and stomach as Israeli warplanes bombed a group of children in Beit Lahiya.
The children were transferred to the Kamal Udwan Hospital, he said.
An Israeli military spokeswoman confirmed the attack but could not immediately identify the target of the strike.
The airstrike followed an unusually quiet night in Gaza after three days of constant bombardment by the Israeli air force.
Tensions in and around the Gaza Strip have soared since Thursday when militants staged a series of bloody shooting attacks in the Negev desert, killing eight Israelis and prompting a wave of bloody tit-for-tat exchanges.
Israel blamed the Gaza-based Popular Resistance Committee for the Eilat attacks, although the group denied involvement.
Since Thursday, 14 Palestinians have been killed, nine of them militants, and 47 injured in Israeli strikes on Gaza, while one Israeli has been killed and dozens injured in a barrage of more than 100 rockets and mortars fired on cities and towns in the south.
On Saturday night, rockets hit the southern city of Beersheva some 40 kilometers from Gaza, killing a man and injuring 15, one of whom was in critical condition, Israeli medics said.
Overnight, Gaza militants fired 17 rockets into Israel.
Shortly after the hit on Beersheva, Israeli Prime Minister Benjamin Netanyahu convened his inner forum to discuss Israel's response to the violence, although a senior diplomatic official quoted by Haaretz insisted the focus was on containment.
"No-one wants an Operation Cast Lead 2," he told the newspaper, referring to Israel's devastating 22-day operation in Gaza over New Year 2009 which killed more than 1,400 Palestinians and 11 Israelis.
That operation, which ended in January 2009 with a truce which has largely held, was launched to stamp out persistent rocket fire on southern Israel.
The Popular Resistance Committees claimed Saturday's deadly rocket fire on Beersheva, while the armed wing of Hamas said it had fired four Grad rockets at Ofakim, lightly wounding two children.
It was the first time the Al-Qassam Brigades had claimed any rocket fire on southern Israel since April when a truce was declared following a similar escalation which saw the air force killing 19 after an anti-tank missile killed a youngster on an Israeli school bus.
But it made no mention of an end to the April 10 truce agreement, which was brokered by Hamas and agreed to by all the main militant factions.
Following the claim, Israel forces began a major operation in the southern West Bank, arresting 120 members of the Islamist Hamas movement, including an MP, Palestinian security sources said.
The military refused to comment on the operation, which the Palestinians said was still ongoing by mid-morning.
In Dura village, youngsters protested the operation by hurling stones at troops, who fired rubber bullets moderately injuring one youngster, medics said.
President Mahmoud Abbas has called for an emergency meeting of the UN Security Council over Israel's attacks on Gaza, while the Arab League was to hold emergency talks on Sunday to discuss the situation, which prompted worried murmurs from the international community.
Maan News Agency