Insurgents launched a pre-dawn attack on Afghanistan's main international airport in the capital, Kabul, on Monday, police have confirmed.
Explosions and gunfire were heard coming from an area that also houses major foreign military bases.
There were no immediate reports of casualties and there was also no early claim of responsibility for the attack.
The airport is home to a major operational base for NATO-led forces that have been fighting Taliban and other insurgents for 12 years.
Police said the attack appeared to be centered on the military side of the airport, to the west of the civilian terminal.