GAZA CITY (AFP) - Israel vowed to escalate its war in Gaza on Saturday after carrying out more deadly air strikes, as troops battled Hamas fighters into a third week despite growing calls for a ceasefire. As the death rose well above 850, Israeli planes sent a cloud of white leaflets fluttering across the Gaza City skyline warning residents it would soon step up its war on Hamas and other militant groups. Ground troops clashed with militants while the air force said it carried out 60 airstrikes targeting arms manufacturing sites, weapons depots and smuggling tunnels, the army said. The Israeli military said it had killed Amir Mansi, a senior Hamas rocket launcher responsible for many of the long-range rockets fired in recent days. Hamas refused to say where he ranked in the movement's armed wing. In a separate incident, eight members of the same Palestinian family, including a 12-year-old, were killed during the shelling of the northern town of Jabaliya."We were at home when the bombing started," one of the attack's survivors Umme Mohammed told AFP inside a nearby hospital. "We fled towards another house and the tanks started firing. Several of us were hit." An Israeli army spokesman denied the incident took place, and Israel has said from the start of the conflict that it is not targeting civilians. Israeli forces killed at least 28 people on Saturday including 17 in heavy fighting in the north and around Gaza City, according to Dr Muawiya Hassanein, head of Gaza emergency services. At least 854 people have been killed since the massive initial air assault on December 27, including 270 children, 93 women and 12 paramedics according to Dr Muawiya Hassanein, the head of Gaza emergency services. Another 3,490 people have been wounded in the fighting, he added. Hassanein explained the surge in casualties by saying that medics had recently pulled several bodies from the rubble in Beit Lahiya and Jabaliya, two areas north of Gaza City that saw fierce fighting on Saturday. The Palestinian death toll previously stood at 828 killed and 3,350 wounded. Ten Israeli soldiers and three civilians have been killed in battle or by rockets launched by Palestinian militants since the start of the war, which is aimed at halting the firing of rockets and mortars into Israel. Hamas and other armed groups meanwhile fired at least 13 rockets into Israel, wounding four people, according to the Israeli army. Hamas has also rejected a UN Security Council resolution calling for an immediate truce in a territory, already reeling from an 18-month Israeli blockade enacted when the Islamist movement seized power. "UN Security Council Resolution 1860 does not meet the demands and interests of the Palestinian people, and harms the resistance," said the joint statement issued in Damascus. The flyers which rained down on Gaza warned that the military "will soon intensify its operations against the tunnels, arms depots, and terrorists throughout the Gaza Strip." "For your security and that of your families, you are asked not to approach terrorists, weapons depots and arms," added the flyers, printed in Arabic. The humanitarian impact of Operation Cast Lead was also becoming more acute with the United Nations warning that families were going hungry as food supplies dry up. Israel launched its war aiming to end rocket fire against southern towns and the smuggling of weapons into Gaza through tunnels under the border with Egypt. Palestinian militants have fired more than 600 rockets, some of them penetrating deeper than ever inside Israel.