Afghan government troops are battling to hold the northern city of Kunduz from advancing Taliban fighters, in a major battle which has seen 10,000 people driven from their homes.
The Taliban push on Kunduz, a city 310 miles north of capital Kabul, is the most serious threat to a provincial capital in years. Kunduz was a Taliban stronghold before 2001.
Government forces have vowed that Kunduz will not fall into the hands of the Taliban, who officials said were fighting alongside foreign jihadists.
Sayed Sarwar Hussaini, a police spokesman, said government forces had held fire to allow civilians to leave the area.
“The Taliban inside the surrounding villages want to use them as human shields, so the villagers have escaped to the central parts of the city,” said Mr Hussaini.
The World Food Programme is preparing food packages for displaced families and expects to start distributing them this weekend.
Mohammad Omar Safi, the governor of Kunduz province, told the BBC that fighters from the Islamic State of Iraq and the Levant (Isil) were “supporting the Taliban, training the Taliban, trying to build the capacity of the Taliban for a bigger fight”.
He said that some 190 Taliban and 20 government soldiers have been killed since the Taliban announced the start of a spring offensive on April 24.
The Taliban forces outside Kunduz, trained by Isil, were more violent because they wanted to die in battle as martyrs, Mr Safi said.
Foreign fighters killed were identified as being from Pakistan, Uzbekistan and Chechnya in Russia.
Mr Safi said the Afghan forces did not have enough air power and their helicopters lacked weaponry. Only a few thousand Nato troops remain in the country, largely in training roles, after their combat mission ended in December.
America will keep 9,800 troops in Afghanistan until the end of 2015 as part of a “training and assistance” mission.