Russian border guards are towing a Greenpeace ship to an Arctic port, where the crew could face charges of piracy for a protest on an oil rig owned by Gazprom.
The Arctic Sunrise was attached to a Russian tug to be taken into Murmansk after the captain refused to steer it himself.
The ship, which is registered in Holland, was boarded by the Russian Coastguard in a helicopter operation on Thursday.
Two crew members from Finland and Switzerland climbed the side of the Prirazlomnaya oil platform in the Barents Sea in the Arctic early on Wednesday in a protest against oil drilling.
They were detained after warning shots were fired. Later they were later taken back to the Arctic Sunrise where the entire crew was placed under arrest and held in the mess.
The ship is due to arrive in the far northern port of Murmansk on Monday or Tuesday.
Thirty members of Greenpeace are aboard the vessel including two New Zealanders. Russia's Investigative Committee says the crew may have committed piracy, which carries a prison term of up to 15 years.
The BBC reports the Gazprom project is Russia's first effort to extract oil from the Barents Sea.
Prirazlomnaya is scheduled to begin production by the end of the year.