Israeli fighter jets attacked in the Hamas-ruled Gaza Strip on Friday morning, sources on both sides said, hours after a rocket fired from the Palestinian enclave hit the Jewish state, AFP reports.
Palestinian security sources said two strikes targeted training sites of Ezzedine al-Qassam Brigades, Hamas's armed wing, in Beit Lahiya in northern Gaza.
In two additional air strikes at sites west of southern Gaza city Rafah two Palestinians were injured, the sources said.
The attack came a short while after a rocket fired from Gaza hit an open area in southern Israel, causing no damage or injuries.
A statement from the Israeli military said that in response to the rocket, its aircraft targeted "a terror activity site and a weapon manufacturing facility in the northern Gaza strip and a weapon storage facility" in southern Gaza.
Tensions have recently risen in and around Gaza after a year of relative calm, with six Palestinians and an Israeli killed since December 20 and militant rocket fire sparking retaliatory air strikes.
On January 22, the army killed two Palestinians, one of them identified by Israel as a militant from the Popular Front for the Liberation of Palestine who the army said was behind recent rocket attacks.
Hamas recently confirmed it had deployed forces in Gaza to "preserve the truce" with Israel, brokered by Egypt, which ended the last major confrontation in November 2012.
While Hamas does not routinely launch projectiles at the Jewish state, Israel says it holds the Islamist group that seized power in Gaza in 2007 responsible for any such attacks.