Six US fighter jets were destroyed and two significantly damaged when insurgents stormed a heavily fortified Afghan base where Britain's Prince Harry is deployed on Friday, a Nato spokesman said.

Lieutenant Colonel Hagen Messer conceded that the scale of damage, carried out by more than a dozen attackers dressed in US Army uniforms and armed with guns, rockets and suicide vests who managed to storm the airfield, was unprecedented.

Three coalition refuelling stations were also destroyed and six aircraft hangars damaged in the assault at Camp Bastion in southern Helmand province, one of the toughest battlegrounds of the war, the US-led Nato force said.

In a statement, it said the attack was "well-coordinated" and carried out by around 15 insurgents, who were organised into three teams and who penetrated the perimeter fence.

"The insurgents appeared to be well equipped, trained and rehearsed," targeting fighter jets and helicopters parked next to the runway, the International Security Assistance Force (ISAF) said in the statement released nearly 36 hours after the assault began.