Oil company BP says 150 people have been evacuated from offshore platforms in the North Sea because of an unmanned barge drifting in rough seas toward the Valhall oil field.

Company spokesman Jan-Erik Geirmo said the evacuees were taken to other oil fields as a precaution, and that 85 people remained on platforms in the Valhall field.

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He said a tug boat was trying to gain control of the barge, which started drifting amid strong winds and high waves late on Wednesday.

Earlier, Norway’s Statoil said one worker was killed and two were injured when a big wave slammed into a drilling rig in the Troll field, also in the North Sea.

Most workers were evacuated from the rig as it headed to shore under its own power.