Christian Aid has welcomed the ceasefire between Gaza and Israel but warns that some people have been badly affected by the latest conflict.
The development agency is calling upon all sides to reach a "lasting, comprehensive and just" peace.
The truce was brokered by Egypt on Wednesday and brought an end to eight days of deadly conflict.
However, Christian Aid was critical of the international community, saying that the current crisis was the "tragic" consequence of the failure to take adequate action after the last major attack on Gaza nearly four years ago.
Janet Symes, Christian Aid's Head of Middle East said that if the ceasefire holds, it could be the first step to meaningful negotiations which she said "have to take place to bring real change to the people of Gaza".
Christian Aid launched an appeal earlier this week to provide urgently needed medical supplies and food, as well as psychosocial support to those most in need.
Symes said: "The people of Gaza are in urgent need of humanitarian support including medical help. The people worst affected by are the poorest – they are struggling to afford food, water and fuel.
"Lifting the blockade on Gaza is essential and we urge all concerned to ensure this promise is turned into reality."
Symes called upon both sides to take steps to ensure the security of Palestinians and Israelis.
She continued: "Renewed peace negotiations must hold all parties to account, be guided by international law, seek to end occupation, lift the blockade of Gaza, and ensure the security of both Palestinians and Israelis.
"Without such efforts, it will not be long before we see yet another outbreak of the kind of violence unleashed a few days ago."