Anti-aircraft guns opened fire on at least one plane high in the sky over the Afghan capital today, and a Defence Ministry official said the army was trying to shoot down a second unidentified aircraft.
Firing was intense for about 15 minutes from anti-aircraft batteries around Kabul and was directed at two planes flying high over the city, a witness said.
The shooting worried a population that is already nervous ahead of anticipated US strikes in pursuit of Saudi-fugitive Osama bin Laden.
Once the anti-aircraft fire started today, one plane disappeared at high speed and the second was seen circling in the clear blue sky over the war-shattered capital. At least one surface-to-air missile was fired at the aircraft as it circled.
A plane is circling at high altitude and we are trying to shoot it down, a Defence Ministry official said, adding he did not know where the plane had come from.
The plane was an unmanned aircraft used for reconnaissance to spot Taliban air defence positions, said one official on condition of anonymity.
The Taliban said they shot down a US spy plane on September 22 near Samangan, 240 km (150 miles) northwest of Kabul, although the Pentagon said it could have crashed because of mechanical failure.
Other provinces are calm. There has been no air intrusion in any part of the country, including Kandahar, the official said, referring to the southern stronghold of Taliban supreme leader Mullah Mohammad Omar.
It was the first time anti-aircraft batteries had opened fire in Kabul since test-firing a few days ago that sent residents scurrying for cover.
An official in Kandahar said military commanders were today preparing for fighting in the face of threats of US strikes.