A group of eight Islamic countries have joined to condemn Israel, accusing the country "repeated violations" of the Gaza ceasefire.
Their statement comes a day after Israeli airstrikes killed at least 30 people in Gaza.
On Sunday Israel began a move likely to attract more criticism when the country's Diaspora Ministry said it would ban medical aid charity Doctors Without Borders, also known as Médecins Sans Frontières (MSF), from working in Gaza.
Qatar, Egypt, Jordan, the United Arab Emirates, Indonesia, Pakistan, Turkey and Saudi Arabia claim Israel's actions "risk escalating tensions and undermining efforts aimed at consolidating calm" in the region.
A joint statement released by the countries' foreign ministries went on to warn that "repeated violations constitute a direct threat to the political process and hinder ongoing efforts to create appropriate conditions for transitioning to a more stable phase in the Gaza Strip".
The statement suggests this could hinder security, humanitarian conditions and US President Donald Trump's peace plan.
Casualties of Saturday's strikes included two women and six children from two different families, officials at the Gaza hospitals which received the bodies said.
The renewed controversy comes as Israel prepares for to reopen the Rafah border crossing, one of the key steps of the US brokered Israel-Hamas ceasefire.
On Sunday Israel announced that the crossing between Gaza and Egypt had been opened as part of a test to assess its operation. It said that on Monday it will be opened for the movement of residents in both directions, but numbers will be limited.
Some 20,000 people in need of medical care are hoping to leave devastated Gaza via the crossing. On the other side of the fence there are thousands of Palestinians in Egypt hoping to return home.
But Israeli Prime Minister Benjamin Netanyahu has said he will allow 50 patients a day to leave. An anonymous official involved in the plans added that they will be allowed to travel with two relatives.
They claimed a further 50 people who left Gaza during the war will be allowed to return each day. But Israel say they will be vetted before crossing and stay under the supervision of European Union border agents.
Some may die before they can leave
The opening of the Rafah Crossing will be symbolically important. But its immediate impact will be limited.
It seems that Israel will allow only very small numbers to go in either direction - a total of up to 150 leaving Gaza each day, comprising 50 people requiring medical treatment, each accompanied by a maximum of two companions, and 50 people going in the other direction.
So this is where the maths comes into play. The only people allowed to enter Gaza are those who left during the course of the war, a number that Israel estimates at 42,000.
At a rate of 50 per day, it would take them more than two years for all those people to get back.
Going in the other direction, Palestinian authorities say there are around 6,000 people requiring urgent medical treatment. At that same rate - 50 people crossing per day - that would mean waiting for about four months for them all to cross.
Palestinian medical sources suggest that some will die of their conditions before they can cross. And it's worth remembering that these are not all people injured by war.
Gaza's health system has been largely destroyed, so people suffering from serious illnesses are all desperate for the treatment they cannot get without leaving.
A few hundred civilians per day is not the busy crisis-cross of people envisaged by some when the peace deal was announced, nor the flow of aid that many hoped for.
It may be that, in the coming days and weeks, the rate of flow is increased, but that will be dependent on Israel’s risk assessment.
It is screening everyone who applies to go in either direction, and that process is not fast. The Rafah Crossing may be open, but not in the way the world might have imagined.
Medical aid for those who have to remain in Gaza could be further limited if the ban on MSF goes ahead.
Israel had suspended the charity's operations in Gaza in December because it refused to comply with new registration requirements for organisations to submit lists of local employees. The charity said the regulations could endanger Palestinian staff.
Now Israel's diaspora ministry says it is "moving to terminate" MSF operations by the end of February. It has said the regulations are aimed at preventing Hamas and other militant groups from infiltrating aid groups.
MSF said they were "a pretext to obstruct humanitarian assistance" and Israeli authorities were "forcing humanitarian organisations into an impossible choice between exposing staff to risk or interrupting critical medical care for people in desperate need".
Israel's diaspora ministry director general Avi Cohen-Scali said MSF had chosen to "violate a public commitment and evade the basic transparency required of any humanitarian organisation".
"If the organisation had nothing to hide, the employee lists would have been transferred to the inter-ministerial team," he said.
Rafah is often considered by Gazans as their gateway to the rest of the world but since 2024 it has been largely restricted by Israel, which claims it had been used by Hamas to smuggle weapons.
The crossing was briefly reopened early last year to allow the evacuation of medical patients.
Earlier this month Hollywood actor Angelina Jolie visited Rafah as part of a humanitarian trip.
The move to finally reopen it indefinitely comes after the remains of the final Israeli hostage were evacuated from Gaza.
It marks a key step in a ceasefire agreement, brokered by Donald Trump's US administration, as it moves into its second phase. Gaza has four other border crossings. But, unlike Rafah, they are shared with Israel.
