Crater left by an Israeli strike on what Palestinian describes as a metal workshop
Three people, including a 14-year-old-boy, have been killed in Israeli air strikes overnight in the Gaza Strip, Palestinian medics say.
The Israeli military said it was responding to mortar and rocket attacks on Thursday on Israel from Gaza.
It said it attacked two tunnels on the border with Egypt, a tunnel to be used by militants for crossing into Israel and a weapons making site.
The strikes hit targets Gaza City, Khan Younis and Rafah.
The militant group Hamas, which controls Gaza, said an Israeli jet had also bombed a building in Gaza City.
On Thursday, Israeli planes dropped thousands of leaflets over the Gaza Strip warning residents to steer clear of the border after Palestinian militants fired mortar rounds into Israel.
Gaza militants have fired more than 280 rockets or mortars at Israel since the end of a devastating offensive against the territory on January 18, according to the Israeli military.
Palestinian groups and human right organisations say about about 1,400 Palestinians died during the offensive. Thirteen Israelis also died in the fighting.