Tens of thousands of Palestinian children returned to United Nations-run schools after the summer holidays on Wednesday, though major US cuts have thrown their funding into jeopardy beyond next month.
Children wearing chequered uniforms and backpacks thronged schools across the Palestinian territories for the first classes of the new school year, AFP correspondents reported.
The UN Relief and Works Agency for Palestine refugees (UNRWA) said all 711 schools it runs for 526,000 pupils in Gaza and the West Bank, Jordan, Lebanon and Syria would reopen in the next few days despite the $300 million US funding cut.
Fears raised by UN chief Antonio Guterres that the schools might not be able to reopen at all failed to materialise but UNRWA warned it might still be forced to close them again in a month if addition new funding is not found.
"At the moment, we do not have enough money to keep the schools open after the end of September," UNRWA spokesman Chris Gunness told AFP.
"At the end of September, UNRWA will be running on empty for all its services, including schools and medical facilities."
In 2017, the United States, which is traditionally the largest single donor to UNRWA, contributed more than $350 million.
But so far this year, it has given just $65 million following President Donald Trump's decision to withhold aid to the Palestinians.
Parents expressed deep concern about the uncertainty hanging over their children's education.
"We are afraid of the schools closing," Soha Abu Hasara told AFP in Gaza City as she dropped her children off for their first day back at school.
"There is fear and the situation is not stable, and there is tension within UNRWA," she said.
UNRWA was formed to support the more than 700,000 Palestinians who fled or were expelled from their homes during the 1948 war that accompanied the creation of Israel.
With their descendants, they now number more than three million across the Middle East.
The United States has sought to use its aid to pressure the Palestinian government into resuming dealings with it after a nearly nine-month rupture.
The Palestinians have boycotted the US administration since it recognised Jerusalem as Israel's capital last December.
Last week, Trump cancelled a further $200 million in aid projects for Palestinians not funded through UNRWA.
Senior Palestinian official Hanan Ashrawi accused the US president of resorting to "cheap blackmail as a political tool".