South Korean troops have fired at a passenger jet flying from China with 119 people on board after mistaking it for a North Korean aircraft, amid increasingly fraught relations on the divided peninsula.

Two soldiers at a guard post on Gyodong island, just 1.7km south of the North Korean coast, fired their K-2 rifles yesterday towards the plane, which was descending as it approached Seoul's Incheon International Airport.

Ties between the two Koreas are at their lowest ebb in more than a decade after Pyongyang announced late last month it was breaking all contacts with the South's conservative government.

The South Korean Asiana aircraft was flying southeast over Jumun island, 12km south of Gyodong, towards Incheon, when the soldiers fired a total of 99 rounds including two blanks, Yonhap news agency said.

‘The firing continued (for) about ten minutes but the plane was too far off the rifle's range and it did not receive any damage,’ Yonhap quoted a Marine Corps official as saying.

‘When the plane appeared over Jumun island, soldiers mistook it as a North Korean military aircraft and fired.’

A Marine Corps spokesman confirmed the incident but declined to give further details.

An aviation controller told AFP that the Asiana Airbus 321 was flying from the southwest Chinese city of Chengdu with 119 people on board, including crew members, and was following a normal route.

‘It was flying normally. It did not deviate from its normal route,’ the controller said.

An Asiana spokesman said there was no damage to the plane as it was too far away from the guard post, adding that the military had inquired whether the plane had suffered any damage.

Following the incident, the Marine Corps will step up training for soldiers to help them distinguish between civilian aircraft and enemy planes, Yonhap said.