The Norwegian Air Force has been left feeling awkward after one of its F-16 jets on a drill mistakenly opened fire on a control tower with three officers who were inside at the time of the mock attack.

An investigation has been started into the grave error, which took place on Tarva, off Norway’s west coast, AFP was told by military spokesman Captain Brynjar Stordal. Astonishingly, no one was injured in the incident.

On April 12-13, two F-16s were performing a mock attack on an enemy station on the uninhabited island, when one of them mistakenly opened fire on the control tower with its M61 Vulcan cannon, capable of making Swiss cheese out of metal and concrete at 100 rounds per second.

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According to Norwegian paper VG, three officers were inside the structure at the time. They said everything happened so fast there was barely time to understand what was going on. Air Force communications manager Stian Roen said it was a very close call, adding that both the control tower crew and pilot are currently undergoing tests.

Remarkably, the very same control tower on Tarva was shot up in 2009, also by mistake. Back then at least one round penetrated the building.