Israel's air strikes against Hamas facilities in the Palestinian Gaza Strip that began Saturday have claimed an estimated 280 lives and wounded 600.

The Israeli Defense Ministry says its main targets have included armories, rocket launch sites and other security facilities of Hamas, the Palestinian Sunni paramilitary organization. He said that around 30 locations in Gaza have been hit thus far.

A Palestinian human rights group said 20 children and nine women were among the dead.

Hamas has declared to fight back, with a spokesman saying they will continue resisting "until the last drop of blood remains" and that "Israel will pay a high price."

The strikes are in retaliation for a recent barrage of rockets that struck Israel, allegedly from the Gaza area.