An Afghan official says troops are being deployed to a key southern city in Helmand province amid intense fighting with the Taliban and fears it could fall to the insurgents within days.

Kareem Atal, head of the provincial council, says Taliban fighters have completely surrounded Lashkar Gah, the capital of Helmand. He says army and police units have been pulled back from checkpoints farther afield and brought back to reinforce the city.

He says that "new forces are arriving" in the city on Wednesday.

The fighting has closed all the highways leading into Lashkar Gah, forcing up prices for food and other basics inside the city.

Helmand is a strategically important province for both the Kabul government and the Taliban, whose insurgency is now in its 15th year.