The president and vice President of the Methodist Conference, Rev Loraine Mellor and Jill Baker said in a joint statement: "We are horrified by the violence that has taken place on the eastern border of Gaza in the past days, and deeply troubled by what appears to be a steady escalation in the situation.
"We appeal to all sides to step back urgently from actions that can only lead to more suffering, and to seek peaceful solutions."
Eighteen Palestinians have been killed as a result of shooting by the Israeli Defence Forces. While reports suggest that as Israel protects its border, it has used live rounds against many unarmed protesters and hundreds of Palestinian demonstrators were hit and injured.
The Church leaders added: "The killing of unarmed protesters is unacceptable in any circumstance and a crime against humanity.
"The Government of Israel is bound by the same standards of international law as any other nation. Live rounds must never be used except in the most critical circumstances to protect life."
Electricity is on for four hours a day, water in many areas of Gaza is undrinkable and there have been reports of Hamas fighters being armed for further conflict.
Clinics and hospitals were already reporting a huge rise in child malnutrition and have said that 80 commonly-used medicines are not available.
The situation is worsened by cuts in funds to the United Nations Relief and Works Agency for Palestine Refugees (UNRWA).
Rev Mellor and Baker said:"We pray for a resolution of the conflict in the region, for the end to occupation and a just resolution for Palestinian refugees.
"We call on the Government of Israel, the Palestinian Authority, and all regional and international powers to do everything possible to prevent a further slide into conflict and bloodshed, to provide humanitarian aid, and to revive the stalled reconstruction of Gaza."
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