All international aid organisations have left the embattled Afghan city of Kunduz amid ongoing unrest there, including a recent US air strike on a charity hospital.
The humanitarian situation in the strategic northern city, briefly captured by the Taliban last month, is thought to be difficult the UN humanitarian agency said on Tuesday (local time).
"There are presently no humanitarian agencies left inside Kunduz city," said OCHA spokesman Jens Laerke on Tuesday.
"Two UN entities, four national NGOs and 10 international NGOs have been temporarily relocated due to the ongoing conflict and unstable and fluid security situation in Kunduz," he told AFP.
A US air strike hit MSF's Kunduz hospital on Saturday, killing 22 people and sparking international outrage, with the charity branding the incident a war crime.
The top US commander in Afghanistan on Tuesday said the hospital had been "mistakenly struck".
The strike came days after the Taliban briefly overran Kunduz in their most spectacular victory in 14 years.
MSF has closed its trauma centre seen as a lifeline in the war-battered region after the incident, while UN Secretary General Ban Ki-moon has called for a "thorough and impartial investigation".
Laerke pointed out that the MSF hospital had been "the only facility of its kind in the entire northeastern region of the country, serving some 300,000 people in Kunduz alone."
Now, he said, "the international aid agencies have been forced out of the city for the time being, so there is essentially no proper healthcare, no proper trauma care for those left inside the city."
In addition, he said water and electricity reportedly remained cut off across much of the city, and most food markets remained closed.
"Thousands of people have fled Kunduz, and an estimated 8500 families have been displaced in the northeast as a result of the fighting," he said, adding that aid agencies were scrambling to gain access to the area so they could assess and address the needs.
The World Health Organization meanwhile announced on Tuesday that it was working with the Afghan Ministry of Public Health to get needed medical equipment and supplies into Kunduz and planned to establish a temporary health facility.