GAZA, July 14 (Xinhua) -- Israeli war jets and drones carried out six intensive airstrikes Saturday on different facilities that belong to the Islamic Hamas movement and other militant groups on the Gaza Strip, slightly injuring two civilians, medical sources and local media reported.

Overnight and just before dawn, Israeli war planes and drones hovered over the coastal enclave, where explosions were heard from time to time until the early morning as a result of the airstrikes.

Local media reported that in response to the Israeli airstrikes, militant groups fired around 20 makeshift rockets and mortar shells from the Gaza Strip into southern Israel. Israeli media reported no injuries.

Fawzi Barhoum, Hamas spokesman in Gaza, said in a press statement that the mission of the militants in Gaza "is to protect our people and defend them."

"The immediate dealing with the escalation of the enemy and the immediate response reflect the status of militants' awareness in running and ruling the conflict, send a clear message and guarantee balance of fast deterrence, and this is done to force the enemy to stop escalation," said Barhoum.

The Israeli airstrikes on Gaza were in response to earlier hand grenade attacks against an Israeli army force in the southern Gaza Strip town of Rafah on the border with Israel.

On Friday, clashes between hundreds of Palestinian demonstrators and Israeli soldiers broke out at the border between the eastern Gaza Strip and Israel, leaving one boy killed and 200 wounded.

The Palestinian Health Ministry said that since the beginning of the rallies and protests called "the Great March of Return and Breaking the Israeli Siege" on March 30, the Israeli army has killed 139 Palestinians and wounded more than 16,000 others.?