Helicopters pulled staff from the Beatrice oil rig in the North Sea because of the approach of a ship carrying radioactive waste, authorities said Wednesday.

Cargo ship Parida, loaded with radioactive waste, caught fire, prompting its crew to shut down the engines to carry out repairs. The vessel started drifting toward the Beatrice oil platform, forcing staff to close operations earlier this week

The Sheltand Coast Guard said two rescue helicopters lifted the 52 people on board the Beatrice rig to safety.

"Ministers have been briefed and Scottish Government officials are engaging closely with the Nuclear Decommissioning Authority, the U.K. Government and key partners to ensure appropriate response arrangements are in place," Scottish Environment Secretary Richard Lochhead said in a statement.

Scottish energy company Wood Group serves as the operator at the Beatrice installation on behalf of owner Ithaca Energy. The Beatrice field came into operation in 1981 and is the largest oilfield in the area, with an estimated 485 million barrels of oil initially in place.