Medics say at least two civilians and two militants have been killed by Israeli air strikes on Gaza, as fresh cross-border violence continues.
The latest strike reportedly killed a 65-year-old man and his 35-year-old daughter in the Jabaliya refugee camp.
Earlier, two Islamic Jihad members died in Khan Younis. A blast also killed a 15-year-old boy in Beit Lahiya.
Sources at Gaza's main hospital say that altogether at least 22 Palestinians, including 18 militants and at least four civilians, have been killed in Israeli air strikes since Saturday.
Israel says more than 240 rockets have been fired into Israel from Gaza since Friday, injuring 35 people, one seriously.
Officials say two exploded near Gedera, 40 kilometres south of Tel Aviv, and another struck the southern city of Ashdod, leaving a woman with moderate injuries.
Resurgence alarms world powers
The cross-border violence was triggered by an air strike on Friday that killed a senior leader of the militant group, the Popular Resistance Committees (PRC), whom Israel said had been planning an attack.
Militants in Gaza responded quickly by unleashing a barrage of rockets towards southern Israel, triggering further air strikes.
The resurgence in violence has alarmed world powers trying to resume the Middle East peace talks.
The United States has condemned the rocket attacks as "cowardly"; the Arab League has called the Israeli air strikes "a massacre".
