(Corrects 2nd paragraph to show the number of activists on the water is 10, not 13)
OSLO, March 22 (Reuters) - Greenpeace activists have boarded a rig that was due to sail to the Arctic to drill prospects on behalf of oil firm Statoil, the environmentalist group said on Thursday.
"We have two people on board and 10 on the water to ensure the rig does not leave port. Our activity started at 8am (0700 GMT) this morning," Truls Gulowsen, the head of Greenpeace in Norway, told Reuters.
"We are prepared to stay as long as necessary," he added. The action took place at the Skipavik yard on Norway's west coast.
The rig belongs to Seadrill and is contracted to Statoil via its North Atlantic Drilling affiliate. (Reporting by Gwladys Fouche, editing by Terje Solsvik)