North Atlantic Refining says it's investigating after a tanker broke free of its moorings during high winds on Boxing Day.

The tanker Horizon Electra was tied up at the refinery in Come By Chance.

The Newfoundland refinery would only say there was "an incident" but sources tell CBC News that moorings holding the ship into the jetty broke, along with two arms used for loading refined products onto ships.

Tugs had to be used to keep the ship at the jetty.

The 183-metre oil tanker didn't appear to be damaged and online ship monitoring websites show it left the refinery Dec. 28 headed for Morocco.

Catherine Rowsell, a spokesperson for North Atlantic Refining, said there were no injuries and no hydrocarbons were released.