Greenpeace activists have boarded an icebreaker off Sweden's south-east coast, staging the second such action this week to protest against oil and gas exploration in the Arctic Ocean.
Greenpeace said six activists climbed aboard the Shell-contracted Nordica after approaching it in rubber boats. About half of them have locked themselves on to the icebreaker.
The organisation is urging Shell to abandon plans to open up the Arctic for oil drilling, warning of a possible oil spill.
Earlier this week, Greenpeace staged a similar action as Nordica was departing from Finland, delaying it by 10 hours.
Two Finnish icebreakers, the Fennica and Nordica, are contracted to support oil and gas production operations on the northern Alaskan coast from 2012 to 2014.