An Israeli airstrike Monday targetted several military sites used by the members of the Islamic Hamas movement in the Gaza Strip.
Israeli warplanes also raided five military bases used by Hamas militants and Islamic jihad group in Khanyoumis and Dier al—Balah cities, south of the Gaza Strip, Xinhua reported.
The airstrikes came a few hours after two rockets were fired from Gaza at Israel.
Security forces in Gaza earlier evacuated their sites and bases on expectation of Israeli airstrikes.
The escalation also followed Israeli accusations that the Hamas movement, which rules the Gaza Strip, was behind kidnapping three Israeli teenagers Thursday near the West Bank city of Hebron.
The Gaza Strip has witnessed sporadic cross-border violence since a cease fire deal was reached between Israel and Palestinian militants in November 2012.
The Egyptian-mediated truce ended a bloody week of violence that left 184 Palestinians and six Israelis dead.
Israeli soldiers kill Palestinian youth
Meanwhile, a Palestinian youth was killed Monday by Israeli soldiers during clashes in the West Bank city of Ramallah.
A 20-year-old man was shot dead during confrontations in Ramallah between Palestinian protestors and Israeli soldiers, Xinhua reported.
These are the first Palestinian casualties since Thursday when Israel announced that three Israeli teenagers were abducted from Hebron city near the West Bank.
The Israeli government has accused the Hamas militant group of abducting the teenagers.