The Disasters Emergency Committee (DEC) , the umbrella organisation of 13 UK aid charities, has launched an emergency appeal for people affected by the conflict in Gaza.
The DEC in a statement said: “After four weeks of terrible fighting… over half a million people have been forced from their homes.
The DEC said its member charities were “rapidly increasing” the assistance provided during the current ceasefire.
The DEC said donations were already being accepted through its website and using a 24-hour phone line.
The DEC will broadcast an emergency appeal on the major television networks on Friday.
DEC chief executive Saleh Saeed said: “After four weeks of terrible fighting Gaza is on the edge. Over half a million people have been forced from their homes, and one and a half million have no or very limited access to water or sanitation.
“Many people are living in terribly overcrowded UN shelters, but they still need food and basic household items which we take for granted. Many are in urgent need of medical care, but hospital supplies are almost finished.
“Even before the conflict began, the people of Gaza were close to breaking point. Now we are seeing a humanitarian emergency affecting virtually every man, woman and child in Gaza.
“The DEC’s member agencies and their partners are on the ground but they need funds to meet the huge needs. They are relying on the generosity of the British people to make a difference.”
The DEC said some agencies had worked through the fighting, while others had responded during lulls in the conflict.
Oxfam is already delivering safe water to up to 175,000 people per day and British Red Cross partners are supporting emergency medical services, it said.
Donations can be made at dec.org.uk, via a 24-hour hotline, over the counter at a bank or post office, or £5 a time by texting the word SUPPORT to 70000.