Israeli military forces have attacked Hamas targets for the third consecutive day in Gaza, hammering the Palestinian Islamist group with missile air strikes and tank shells Saturday, killing at least four Arab militants.

Israeli missiles hit a car near Rafah in southern Gaza, which killed three Hamas militants, including a commander Tayser Abu Snima. Later, another tank shell struck and killed another militant near the Jabalya neighborhood in Gaza.

In exchange, Hamas and Islamic Jihad fired fifteen rockets into Israel near the cities of Ashdod, Ashkelon and Beersheba. No Israelis were hurt in the attacks. Israel’s new Iron Dome defense system has been instrumental in defusing Hamas missiles and shelling.

Not since the Israeli military campaign in 2008-2009 has Gaza seen such violence.

An attack by Hamas missiles on Thursday that wounded two Israelis on a school bus has prompted this unyielding offensive by the Jewish state.

Israel’s Prime Minister Benjamin Netanyahu said the attack on the school bus crossed a line and warned that whoever tries to harm and murder children will pay with their life.

Hamas said the school bus attack was itself retaliation for Israeli strikes that killed three militants earlier last week.

Thus far, since Thursday 18 Gazans, including civilians have died, and dozens have been wounded.

Hamas spokesman Sami Abu Zuhri said Saturday that his group's attacks in Israel were limited and controlled but warned that if Israeli persisted in committing strikes, Hamas would escalate the war.

The occupation government is responsible for this escalation, Zuhri told reporters in Gaza. We want to make a clear point that we shall not allow them to achieve their goals and they must know that they will fail to force the Palestinians to give up.