Nato's main military base in southern Afghanistan has come under rocket and mortar fire.
A Nato spokesman said insurgents fired on Kandahar airbase and followed up with a ground assault.
Officials said the attackers had tried to get into the base, but were repelled. Several Nato personnel were wounded, the BBC reports.
Afghan contractors said five rockets struck the base, including one which hit the helicopter base and another which targeted a shopping area.
It was the second assault on a major installation in the last few days.
On Wednesday, an American contractor was killed in fighting that lasted several hours when militants attacked the US military base at Bagram.
Nato also said that separate attacks in southern Afghanistan earlier on Saturday killed three Nato personnel and a civilian working with the military.
The Taliban recently announced a spring offensive against Nato forces and Afghan government troops.
Nato commanders at Kandahar oversee more than 54,000 troops in southern Afghanistan.