DHAKA: The Taliban on Friday claimed responsibility for an apparent ‘insider attack’ at Kabul airport in which three American contractors and an Afghan were killed.

A spokesman for NATO’s Resolute Support mission said the incident is under investigation. Though, details of the Thursday evening shooting are still unclear, reports NDTV.

A US defence official in Washington said that the American victims, who were employed under a US Defense Department contract to help train the Afghan air force, died from gunshot wounds.

Taliban spokesman Zabihullah Mujahid said a member of the insurgent movement was responsible for the attack.

“A brave Afghan mujahid infiltrator working in the military side of Kabul airport opened fire on invading American soldiers, killing three Americans,” he said in a statement sent to media.

Western troops and civilians training Afghan security forces have faced lethal assaults from Afghans in uniform who turn their guns on their counterparts.

At least nine people were killed earlier Thursday in the country's east when a suicide bomber struck at a funeral for victims of a roadside bomb attack.

BDST: 1537 HRS, JAN 30, 2015