Greenpeace ship "Arctic Sunrise" is seen anchored outside the Arctic port city of Murmansk September 24, 2013. REUTERS/Stringer

MOSCOW (Reuters) - Russia rejected a ruling by an international arbitration court which said Moscow must pay damages for seizing a Dutch-flagged Greenpeace vessel, saying on Thursday that the decision would only encourage illegal protests.

Russian Federal Security Service agents captured the vessel -- the Arctic Sunrise -- in international waters in 2013 after a protest against an oil platform. Those on board were detained in Russian prisons for months and released shortly before the 2014 Sochi Olympics.

The international arbitration panel, based in Vienna, on Tuesday said that Russia must pay the Netherlands more than 5 million euros ($5.82 million) in damages for seizing the boat and arresting the people aboard.

“We have to state with regret that by its actions the arbitration panel is in fact encouraging deliberately unlawful action in states’ exclusive economic zones and on their continental shelf, justifying it as so-called ‘peaceful’ protest,” Artyom Kozhin, a Russian foreign ministry spokesman, told a news briefing.

Kozhin said that the panel’s original decision that Russia was liable, dating back to 2015, did not take into account “a direct threat to the safety of the (oil) platform and its personnel created by the actions of Greenpeace activists”.

“The relevant Russian bodies were forced to act to use lawful steps to stop the dangerous illegal behavior”, said Kozhin.

Russia had originally declined to take part in arbitration, arguing that it was acting within its sovereign rights to seize the ship in international waters where Russia enjoys exclusive economic rights.

Activists had earlier tried to scale the Prirazlomnaya drilling platform, operated by Gazprom.