More than 120,000 people have fled their homes but have nowhere safe to go Oxfam says.

With exit through Israel closed under the long-term blockade, and the border with Egypt shut, most people are prevented from escaping the violence.

Um Mohammed Al Azazma, a mother of eight, told Oxfam: "Everyone was running and scared while carrying their children and the tank shells falling around us.

"I had to jump over dead bodies in the streets. The schools were full and we ended up in a church.

"My children are scared and we try to convince ourselves that we are in a safe place, but there is no safe place in Gaza right now. The only thing we need is to be safe in our homes."

Conditions in the schools are becoming increasingly desperate, with clean water, food and shelter running perilously low. Oxfam is trucking vital supplies of safe water to 19,000 people sheltering in schools, a church and a mosque.

Oxfam is also delivering water to Al Shifa hospital, which has seen a massive influx of civilian casualties in the past few days, including many women and children. Hospitals and health facilities have themselves been hit and seriously damaged.

"The terrible toll on civilians is shocking. Hospitals and water supplies are under massive strain and the needs are increasing by the day. People are fleeing terrified. Normally in crises like this we would see an exodus of people escaping the violence, but in Gaza there is no safe place for them to go.

"For years the blockade has prevented most people from leaving Gaza, restricted trade and devastated the economy. Lasting peace and security for both sides means ending the blockade and the collective punishment of people in Gaza," said Nishant Pandey, head of Oxfam in the Occupied Palestinian Territory and Israel.

Damage to water and electricity systems has disrupted the supply of water to over 1 million people.

Destruction of sanitation plants risks raw sewage contaminating the water and increasing the risk of disease. Only half of Gaza's sewage plants are now working. Most of Gaza is now only receiving power for four hours a day or less.

The ongoing violence and intensive airstrikes makes it extremely difficult and dangerous to deliver aid to people, despite the growing needs.

Many Oxfam staff and partners have themselves been affected by the violence and have had to leave their homes.

Oxfam says it condemns violence against civilians by all sides, including Israeli military actions and Palestinian rocket fire.