Taliban fighters have taken control of 10 villages in the Arghandab district of Kandahar province in Afghanistan, and have said they plan to march towards Kandahar city.
Mohammad Farooq, a government official in Arghandab, said on Monday that around 500 Taliban fighters moved into the area and took over the villages.
Arghandab lies 30km north of Kandahar city.
Haji Ikramullah Khan, a tribal leader from the region warned that the fighters could use the cover of the district's grape and pomegranate orchards to mount an attack on Kandahar itself.
"All of Arghandab is made of orchards. The fighters can easily hide and easily fight," he said.
"It is quite close to Kandahar. During the Russian war, the Russians didn't even occupy Arghandab, because when they fought here they suffered big casualties."
The Taliban offensive follows the escape of more than 1000 Taliban andother prisoners in a suicide attack on the main jail in the southerncity of Kandahar on Friday night, which also left many prison guardsdead.
Mark Laity, a Nato spokesman, said that Nato and Afghan military officials were redeploying troops to the region to "meet any potential threats".
"It's fair to say that the jailbreak has put a lot of people [fighters] into circulation who were not there before, and so obviously you're going to respond to that potential threat," he said.
Al Jazeera's Hashem Ahelbarra, reporting from Kandahar, said that hundreds of Taliban fighters are taking up positions in the area and taking over nearby villages.
"Ultimately, it is local residents who are paying a heavy price for this increasing instability," he said.
"The Taliban are showing impressive capability in manoeuvring in and around the area."