Three Afghan officials tell The Associated Press that the Taliban have entered the outskirts of the capital, Kabul.
The officials, speaking on the condition of anonymity as they weren't authorised to release the information, said there hadn't been any fighting yet.
The Taliban fighters were in the districts of Kalakan, Qarabagh and Paghman.
The insurgents did not immediately acknowledge their presence in the capital. However, government offices suddenly began sending workers home early Sunday as military helicopters buzzed overhead.