Jerusalem, Oct 29 : Societal order is beginning to collapse in the besieged Gaza Strip after thousands of desperate people raided UN warehouses in search of food, amid continuing bombardment by Israeli airstrikes and a widening ground offensive as the war enters its fourth week, a media report said. Thomas White, the head of the UN's agency for Palestinian refugees (UNRWA), said on Sunday that wheat, flour and hygiene supplies had been taken overnight from several UN-run centres across the blockaded 41 km by 12 km strip, home to more than 2 million trapped people, The Guardian reported. 'This is a worrying sign that civil order is starting to break down after three weeks of war and a tight siege. The needs of the communities are immense, if only for basic survival, while the aid we receive is meagre and inconsistent,' White said. Basic services in Gaza have crumbled after three weeks of a near-total siege, leaving people exposed to serious outbreaks of disease as streets overflow with sewage, and food, water and medicine run out, The Guardian reported. Israel sharply escalated an already devastating aerial campaign on the coastal exclave on Friday night that has killed more than 8,000 people, according to the Hamas-run health ministry. Under the cover of strikes and artillery, Israeli ground troops have begun moving into the north of the strip, in the areas of Beit Lahia and Beit Hanoun in what Israeli Prime Minister Benjamin Netanyahu described as the 'second stage of war' triggered by Hamas' rampage across southern Israel on October 7, when it killed 1,400 people and kidnapped 230 hostages, The Guardian reported. The Israel Defence Forces (IDF) said that over the last 24 hours, they had hit 450 targets belonging to Hamas, the Palestinian militant group that seized control of Gaza in 2007, including command centres, observation posts and anti-tank guided missile launch positions, as well as another 150 targets underground in the north of the territory. Ground fighting was also reported to the east of the Bureij refugee camp and the city of Khan Younis in central Gaza -- approach routes for Israeli incursions in the past, the report said. /IANS