A humanitarian truce in the Gaza Strip collapsed on Sunday after a barrage of rockets fired by Palestinian militants was met with fierce Israeli shelling, in a fresh setback to efforts to secure a permanent cease-fire.

Israeli tanks and artillery pounded targets along the coastal enclave, sending thick plumes of black smoke rising into the sky, signaling an end its unilateral, 24-hour truce in the wake of the missile salvoes.

Palestinian witnesses reported heavy shelling east of Gaza City, with ambulances immediately racing towards the area. At least three deaths were reported in separate strikes. More than 1,000 people, mainly civilians, have been killed in Gaza.