Three soldiers were seriously injured when the British Apache gunboat fired on a location thought to be held by insurgents, The Guardian reported Friday. Six others soldiers were treated and returned to their unit.

Two of the seriously injured soldiers were hospitalized at Camp Bastion, the main British base in Afghanistan, and the third was evacuated to a hospital in Birmingham, England, The Independent reported.

British army officials said the incident occurred Thursday when the patrol called in air support during a skirmish in Helmand province.

"After successfully engaging one enemy position the Apache fired upon another position which the crew believed to be held by enemy forces," a Defense Ministry spokesman said. "However, in the confusion of a rapidly changing situation and, in what is a challenging environment, it would appear that friendly forces were mistaken for the enemy and as a result three members of the patrol were seriously wounded and six more were classified as walking wounded."