The Afghan army is sending reinforcements to the capital of the key southern province of Helmand to reverse the Taliban gains in the area.
According to Kareem Atal, the head of Helmand's provincial council, Taliban militants have completely surrounded Lashkar Gah and there are fears it could fall to the militants within days.
Atal said army and police units have been brought back from checkpoints farther afield to reinforce the city and “new forces are arriving” in Lashkar Gah.
The fighting has led to the closure of all the highways leading into Lashkar Gah, forcing up prices for food and other basics inside the provincial capital, he said.
Meanwhile, Guilhem Molinie, Doctors Without Borders' representative in Afghanistan, said the medical charity has reduced its international staff in Lashkar Gah and is maintaining basic emergency and surgical services.
The charity, known by its French acronym MSF, has a 300-bed hospital in the city and usually functions with 25 international staff.
Molinie said that the number of people arriving for treatment after being caught up in fighting in districts around the city had been reduced in recent days due to road closures.
Omar Zawak, a spokesman for Helmand's governor, warned on Tuesday that the provincial capital was struggling to cope with an influx of people fleeing fierce fighting across the troubled region.
NATO has voiced concern over the intensity of the ongoing battle in Helmand.
Helmand is a strategically important province for both the Afghan government and Taliban militants, who effectively control or contest 10 of the 14 districts in the opium-rich province.
The militants have stepped up their attacks in the province in recent months.
Afghanistan faces a security challenge years after the United States and its allies invaded the country in 2001 as part of Washington’s so-called war on terror. The offensive removed the Taliban from power, but many areas in the country are still beset with insecurity.