Israel struck several targets in the eastern and southern parts of Gaza on Friday night, wounding at least four people, witnesses and medical sources said.
Witnesses said Israeli F16 fighter jets fired two missiles and tanks fired two shells that landed at empty areas east and northeast of Gaza City. They said huge explosions were heard in the area.
Ambulances took four people to Gaza hospitals for medical treatment, according to medical sources. The four were lightly injured.
Meanwhile, residents said Israeli warplanes carried out a fifth raid on a post belonging to militants from the Islamic Hamas movement in the southeast of the Gaza Strip. No injuries were reported.
The five successive air and ground strikes came hours after militants from the Popular Front for the Liberation of Palestine (PFLP) claimed responsibility for firing two Russian-made Grad missiles Thursday night from Gaza at southern Israel.
The Popular Resistance Committees (PRC) also claimed responsibility Friday for firing four mortar Shells at Israeli army vehicles near the border between southeast Gaza and Israel. No injuries or damages were reported.
Israeli Radio reported earlier Friday that two Grad rockets fired from the Gaza Strip landed Thursday night in southern Israel, one hitting the southern town of Netivot.
The Color Red early warning system did not go off Thursday, giving residents no indication of the coming attack.
One woman suffered shock and no damage was reported.
This was the first such attack on Netivot in nine months. The last Grad rocket to hit the city exploded near a synagogue, causing some damage.
Netivot Mayor Yehiel Zohar contacted the Israel Defense Forces demanding to know why the early warning system failed to work.
Prime Minister Benjamin Netanyahu threatened this week that the Israel would respond to every single rocket by Gaza militants.
The escalation of violence between Israel and Gaza militants comes as Palestinians on December 27 marked one year since Israel's three-week-long military offensive in the Gaza Strip that left more than 1,400 people dead.