Gaza City (Palestinian Territories) (AFP) - The Israeli air force carried out attacks on Hamas sites in the Gaza Strip early Saturday, Palestinian security sources said, just hours after rockets from the enclave hit southern Israel.

According to the sources, the Israeli strikes targeted four empty facilities ranging from Beit Hanoun in the north to Rafah in the south, causing damage but no casualties.

The Israeli army said its "aircraft targeted two Hamas military training facilities and two military sites in the Gaza Strip".

"The IDF holds Hamas responsible and accountable for all attacks emanating from the Gaza Strip," a statement read.

Late Friday, two rockets fired from Gaza hit southern Israel, without causing casualties or damage.

Since the end of the devastating war between Israel and Gaza militants in the summer of 2014, nearly 30 projectiles fired from the Hamas-controlled Palestinian enclave have hit the Jewish state, according to military data.

Sunni militants claiming links to the Islamic State jihadist group have said they were behind rocket fire from the Palestinian enclave in recent months, but Israel holds Gaza's Islamist rulers Hamas responsible for all such incidents.

Also on Friday, two Palestinians were slightly wounded by Israeli gunfire after they stormed the border fence in northern Gaza, the Israeli army and Gaza medics said.