Palestinians say corpses are littering the streets as casualties litter the blood-stained emergency room floors of Gaza's hospitals, a third of which have been damaged in the fighting.Almost half a million people - 460,000 or a quarter of all Gazans - have been displaced with 270,000 crammed into 90 desperately crowded UN shelters, some of which have had no running water for two weeks.The crisis escalated today after Israel attacked another UN school killing 10 people, many of whom were waiting in line for food handouts, in what the UN Secretary-General called 'yet another gross violation of humanitarian law'. More rockets were also fired towards Israel, intercepted by its defences.The UN has warned Gaza's medical facilities are 'on the verge of collapse' after a third of its hospitals, 14 clinics and 29 ambulances were damaged.Two-fifths of Gaza's medics are unable to get to work because of the violence and treatment is thrown into chaos by anonymous false alarms of impending attacks. Many of those in shelters are reliant on bottled water as the total amount of British aid pledged to the crisis reaches £13million.   Sanitation facilities are badly damaged and Gaza City only receives two hours of electricity per day, the UN added. Some areas have no electricity at all and one shelter in Jabalia is holding 10,000 people. Dr. Ambrogio Manenti, acting Head of Office of the UN World Health Organization, said: 'The ability to provide necessary healthcare is being severely compromised. This puts the lives of thousands of Palestinians in needless danger'.Robert Turner, Director of Operations in the Gaza Strip for the UN Relief and Works Agency, said: 'Hundreds of thousands of people are sheltering in terrible conditions, pushing UNRWA's coping capacity to the edge.'(dailymail.co.uk)Bakudaily.az