Palestinian security sources said Israeli planes fired at least four missiles early Fridayat an uninhabited area north of Beit Hanoun, but caused no injuries.
An Israeli army spokesman in Tel Aviv said the planes had carried out "several raids" against access roads for sites from which rockets had been fired into Israeli territory.
Earlier on Thursday, a makeshift rocket fired by Palestinians from the Gaza Strip hit the outskirts of the Israeli city of Ashkelon, the army said.
The Qassam rocket, which takes its name from the armed wing of the Islamist movement Hamas, landed in sand dunes by an industrial zone of the city which lies around 10km north of Gaza. No one was injured.
The Israeli army responded initially by shelling the uninhabited areas from which the rockets were fired.
The armed wing of the radical Islamic Jihad group, the Al-Quds Brigades claimed responsibility for the rockets.
Israel has launched a number of air strikes on Gaza in recent days in response to Qassam attacks and a suicide bombing in the city of Netanya on 5 December.
Four Palestinian fighters from the Popular Resistance Committees were killed in Wednesday's air strikes.