Three days after the Iran-Israel ceasefire took effect, the first organized convoys of displaced families began crossing back into Iranian border provinces and southern Iraq on Saturday, opening a tentative new phase of the six-week war’s aftermath even as humanitarian agencies warned that the pace of returns was outrunning conditions on the ground.

The U.N. High Commissioner for Refugees said roughly 4,200 people had been registered as moving back through border posts at Bazargan, Mehran and the Shalamcheh crossing since the early morning hours of April 17, with another estimated 9,000 expected over the weekend. The figures represent a small fraction of the roughly 1.1 million people displaced inside Iran and the additional 380,000 the agency said had crossed into neighboring countries since the conflict began in early March.

“What we are seeing is the very beginning of what will be a long and uneven process,” said Mariana Voss, a UNHCR senior coordinator in Erbil who oversees the agency’s response across the Iran-Iraq corridor. “Families want to go home. That is entirely understandable. Our job is to make sure they go back to homes that still exist, with water, with power, and without unexploded ordnance in the yard.”

The early movement has been concentrated in areas that escaped the heaviest bombardment, including villages south of Tabriz and townships in Khuzestan province that hosted displaced populations rather than experienced strikes. In Iraq, families who fled Houthi-linked rocket fire from western Anbar and from the outskirts of Basra began trickling back overnight, according to the Iraqi Ministry of Migration and Displaced, which set up reception points at four locations.

Conditions in harder-hit areas remained far less settled. Tehran’s southern industrial belt, the city of Isfahan and parts of the Bushehr coastline — all sites of Israeli strikes during the war — are still without reliable electricity, and water service has been described as intermittent at best. Iranian state media on Friday cited Energy Ministry estimates that more than 40 percent of pre-war generation capacity in the worst-affected provinces was either damaged or running on emergency diesel.

“It is not realistic to expect families to return to Isfahan this week,” said Hossein Mahmoudi, a Tehran-based researcher with the Iranian Red Crescent Society, in remarks carried by the semi-official ISNA news agency. “We are advising people who have housing options elsewhere to stay where they are for at least another two weeks while we complete damage surveys.”

International Committee of the Red Cross teams entered Yemen’s Hodeidah port on Friday and began an initial assessment of facilities damaged in the final week of strikes, the organization said in a statement. Yemen, which absorbed both U.S. retaliatory strikes against Houthi positions and the displacement of an estimated 110,000 people from coastal districts, presents what relief officials describe as the most complex humanitarian picture of the post-war phase.

“Yemen was already the world’s largest humanitarian operation before March,” said Anders Lindgren, the ICRC’s regional head of operations, speaking by phone from Sana’a. “What this war added was not just new damage but a near-total disruption of the logistics we had spent years rebuilding. Restarting those supply lines is the immediate priority.”

The U.N. Office for the Coordination of Humanitarian Affairs on Friday issued a revised flash appeal seeking $1.8 billion for the next 90 days, more than triple its pre-war funding ceiling for the region. Officials said the appeal would cover food, shelter, medical care and mine-clearance work across Iran, Iraq, Yemen and Lebanon, where Hezbollah-controlled neighborhoods in southern Beirut sustained significant damage during the war’s middle weeks.

European donors signaled openness to the request. A spokesperson for the European Commission’s humanitarian aid arm said Brussels was prepared to commit an initial 240 million euros if member states approved the package next week. Gulf states have so far focused their own pledges on bilateral channels, with Saudi Arabia and the United Arab Emirates announcing on Thursday a combined $750 million package directed primarily at Iraqi reconstruction.

The status of foreigners detained inside Iran during the conflict — a separate humanitarian thread the war produced — moved toward partial resolution Saturday in Doha, where the prisoner exchange brokered as part of the Islamabad framework was expected to begin its first phase later in the day. Roughly 40 detained foreigners, along with the remains of several U.S. service members killed during the conflict, are to be handed over in exchange for Iranian and Hezbollah-affiliated detainees held by the United States and Israel.

Aid workers said that exchange, while welcome, would not address the broader question of civilians inside Iran who lost access to identity documents, bank accounts and property records during the bombings. A working group convened by the U.N. Development Programme is expected to release recommendations next week on document reconstitution, an issue that proved highly disruptive in the years after the 2006 Lebanon war.

For now, the principal concern of agencies on the ground is the gap between what families want and what is safe. UNHCR has asked all parties to support a “phased and informed” return rather than mass movement, and Iranian authorities have so far supported that posture, slowing the reopening of certain interior provinces to returning residents.

“We are not telling anyone they cannot go home,” Voss said. “We are asking them, please, to wait until we can tell them where home still is.”

Officials said additional border crossings and assessment teams would be activated in the coming week as damage surveys progressed.