A bomb threat in which hundreds of workers were evacuated from an oil rig in the North Sea Sunday was sparked by a hoax caller, Sky News reported.

A spokesman for Grampian Police said a 23-year-old woman was being taken on shore Sunday for questioning after she made comments about a possible security situation on the installation, it was reported.

"We are investigating an alleged incident on a North Sea installation ... The incident, which was reported to Grampian Police force control room at 9:30 a.m. today is not considered terrorism-related," the spokesman said.

Following the alert, a fleet of 14 military and coast guard helicopters evacuated 539 workers from the Safe Scandinavia rig, 170 miles off the coast of Aberdeen, in eastern Scotland.

The workers, taken to nearby platforms, have now been returned and the evacuation has ceased, Sky reported.

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