An Israeli military helicopter fired three missiles at a car south to Gaza City on Wednesday afternoon killing three Hamas activists, Palestinian sources said. Three people were said to have been killed in the explosion. Hamas officials said the dead were members of Hamas military wing. The Israeli army confirmed the targets of the attack were "senior Hamas officials." The dead were identified as Amer Hassan, 25, Tarad al Jamali, 24, and Ibrahim a-Diri, 38. Hamas leader, Abd al-Aziz al Rantissi, threatened that the movement would respond with a military strike. He said, "even if the Hamas members were on their way to carry out a legitimate attack on the settlement of Netzarim, a military response to the action will be forthcoming. Before (Ariel Sharon) withdraws from Gaza, he continues to carry out crimes against the Islamic movements in the Strip." Witnesses reported at least two blasts as well as gunfire and a power outage as Israeli aircraft flew over the area, not far from the Netzarim settlement. A day earlier, the Israeli military announced it would heighten its battle against Palestinian groups. "In wake of the intensification of the activities of the terrorist organisations over the last few weeks, we will intensify our anti-terror operations," the Israeli military's chief of staff, General Moshe Yaalon (Bugi), told Army Radio. **PHOTO CAPTION*** The skeleton of a Palestinian car hit by Israeli missiles in Gaza City is seen after the air strike. (AFP/Mohammed Abed)