Jerusalem, Dec 4 : Israel's military chief Herzi Halevi has said that the military has expanded the ground operation against Hamas to the southern Gaza Strip, an area previously considered as a "safe zone". "We fought strongly and thoroughly in the northern Gaza Strip, and we are also doing it now in the southern Gaza Strip," Halevi, the chief of the General Staff of Israel Defense Forces (IDF), said on Sunday during a tour at Israel's Gaza Division outside the besieged enclave, according to a statement released by the military. He said that the Israeli ground troops, in combination with air and sea forces, have almost completely "dismantled" two Hamas brigades, killing brigade commanders, company commanders, and "many" operatives, Xinhua news agency reported. Halevi said that on Saturday morning, a day after a fragile seven-day ceasefire between Israel and Hamas had collapsed, the forces "started the same process in the southern Gaza Strip." He vowed that the offensive in the southern Gaza Strip "will be with no less strength than that, it will be with no fewer results than that, and Hamas commanders will meet the IDF everywhere in a very, very strong way." Halevi added that the offensive in the northern Gaza Strip would continue with full force. The expansion of Israel's ground operation has heightened concerns over the severe humanitarian crisis in Gaza. "People have lost everything, and they need everything," the United Nations Relief and Works Agency for Palestinian Refugees (UNRWA), wrote on the social media platform X. "Gaza's population will soon begin dying from diseases as well as Israeli bombardment," the agency warned. Meanwhile, rocket fire from Gaza continued on Sunday, targeting mainly southern Israeli communities. Rockets and anti-tank missiles were launched at northern Israel from Lebanon, lightly injuring at least four people in the community of Beit Hilel in the Galilee, according to Israel's Magen David Adom rescue service. In the Golan Heights two projectiles were identified crossing from Syria in two separate incidents, the Israeli army said in a statement, adding that troops fired towards the area from which the projectiles were launched. Despite the continuation of rocket fire, Israel's Homefront Command announced that all restrictions on schools and workplaces have been lifted, allowing the resumption of all activities, except in the southern communities adjacent to the Gaza Strip, where schools have been closed since the beginning of the war and remained so. More than 15,000 people have been killed in Gaza since the beginning of the Israel-Hamas conflict, with 75 per cent of them being children, women, and the elderly, and 41,316 others were injured, according to the Gaza-based Media Office. Israeli authorities said about 1,200 people were killed on the Israeli side. /IANS