Gaza medical officials said two predawn attacks on houses in the Jebalya refugee camp in killed one child and wounded 12 other people overnight Saturday.
Another strike targeted a building in Gaza City housing the offices of local Arab media, wounding three journalists from al Quds television, a station Israel sees as pro-Hamas, witnesses said.
These attacks followed a defiant statement by Hamas military spokesman Abu Ubaida, who told a televised news conference.
"This round of confrontation will not be the last against the Zionist enemy and it is only the beginning."
The masked gunman dressed in military fatigues insisted that despite Israel's blows Hamas "is still strong enough to destroy the enemy."