The emergency in areas of Afghanistan hardest hit by flash floods that killed hundreds of people "remains critical", the World Health Organization said, with authorities on Wednesday predicting more bad weather.
Taliban authorities and the World Food Programme said more than 300 people were killed at the end of last week when flash floods ripped through several provinces in Afghanistan.
Destruction of roads and swollen waterways have hampered rescue efforts and made it difficult for aid teams to reach many of the worst-affected areas, with northern Baghlan province the hardest hit.
"The flood emergency situation in Baghlan province... remains critical," the WHO said in a situation report late on Tuesday.
"Thousands of individuals are still displaced, urgently requiring food, shelter, and immediate health services."
UN agencies and Taliban officials have warned that death tolls could rise, with internet disruption making it difficult to assess the situation in some villages, days after the disaster hit.
NGOs and the government have reported thousands of houses damaged and destroyed, livestock lost and acres of land ruined, but there are disparities in exact figures.
"Aid agencies continue facing substantial challenges in reaching affected populations due to the extensive damage to transportation infrastructure, including roads and bridges," the WHO said.
More bad weather could further stall aid, with the Afghan weather department warning of more rain in parts of Baghlan and other northern provinces in the coming days.
Afghanistan, which is "exceptionally vulnerable to flooding" has seen above-average rainfall this spring, Mohammad Assem Mayar, a water resource management expert, said in an Afghanistan Analysts Network report.
The rains come after years of drought in a country that is one of the most vulnerable to climate change, according to experts.
The UN's WFP warned that the floods have compounded an already dire humanitarian situation.
"With these erratic weather patterns, it's been disaster after disaster, pounding communities back into destitution, over and over again," WFP Afghanistan head of programme Timothy Anderson said at a news briefing on Tuesday.
Afghanistan, ravaged by four decades of war, is one of the world's poorest countries, with 80 percent of its more than 40 million people dependent on agriculture to survive.