The incident took place at a facility used by the Afghan air force at about 1100 local time (0630 GMT), the Afghan defence ministry said.

The pilot was also killed in the exchange. The incident is the deadliest of a number of recent attacks on foreigners by Afghan security personnel.

US officials said the eight Isaf troops and one foreign contractor were all American, AP news agency said.

Witnesses reported hearing sirens and seeing a heavy military presence near the facility, which generally has tight security.

A senior Afghan security official said that the pilot's name was Gul Ahmad, and he came from the Tarakhel area of Kabul.He was suffering from "mental illness", and either got into a fight with his foreign colleagues or planned the attack after being recruited by the Taliban, the official said.

A spokesman for the Afghan Air Corps, Col Bahader, told AP the shooting was in an operations room of the Afghan Air Corps.

The Taliban claimed responsibility for the incident in a text sent to AP but the authorities have not confirmed any insurgent activity.

Until now the deadliest of the recent attacks on foreign troops was last November when an Afghan policeman killed six US soldiers.