The Afghan authorities say five people have died and 25 are missing in flash floods in the south of the country.
By Catherine Davis
BBC correspondent in Kabul
A spokesman for the governor of Helmand province said five houses had been destroyed in the Baghni Baghran district, as well as roads and farmland.
Floods have also swept through villages on the Shomali plains, north-east of the capital Kabul.
The United Nations, aid agencies and government officials have held an emergency meeting in Kabul to co-ordinate relief.
Village elders in Helmand say these are the worst floods in 50 years.
Many of those missing are women and children. Houses have been washed away and precious farmland destroyed.
Afghanistan's long drought is over
Local officials have appealed to the central government to send help by helicopter, since access by road is now difficult.
The UN said about 200 families were rescued by helicopter from the Shomali plains near the Gorban river. Some people escaped to higher ground, but many were trapped in their homes, as water levels rose quickly overnight.
Three children are said to be missing.
The rescue operation began on Saturday morning. A delegation from Kabul went to assess what help should be provided.
The drought which gripped Afghanistan for three consecutive years is over.
Southern provinces such as Helmand, now hit by floods, were among the worst affected.