Israel has carried out a series of air attacks on the Gaza Strip.
The Palestinian Health Ministry says at least 17 people have been injured in the attack on Monday.
The BBC reports that for over an hour planes could be heard in the skies above Gaza. There have been reports of up to nine explosions in Gaza City, and in the north and south of the territory.
Several militant training camps operated by Hamas are believed to have been targeted, as well as a workshop and cement factory.
The Israeli military would not confirm details of the operation.
Many Hamas buildings in Gaza had been evacuated in anticipation of Israeli military action after militants from the Islamist movement said they had fired a barage of mortars into Israel on Saturday.