MOSCOW (Reuters) - Russia shrugged off Dutch legal action over its detention and prosecution of Greenpeace activists for piracy, saying on Saturday the group's protest at an Arctic oil platform had been "pure provocation".

The Netherlands launched legal proceedings against Russia on Friday, saying it had unlawfully detained activists and others on the Dutch-registered ship last month as it protested against drilling in the Arctic.

Two Dutch citizens were among 30 people on board the Arctic Sunrise, which was seized by Russian authorities near the Prirazlomnaya offshore oil platform.

Deputy Foreign Minister Alexei Meshkov told state-run news agency RIA Novosti Russia had repeatedly asked the Netherlands to halt what Russia said was "illegal activity" by the ship.

"Unfortunately, this was not done. Therefore, we have far more questions for the Dutch side than they can have for us," RIA quoted Mr Meshkov as saying.

"Everything that happened with the Arctic Sunrise was pure provocation."

The Russian authorities have pressed piracy charges, which could result in prison sentences of 15 years.

The Dutch government contests the "unlawful manner" in which the ship was intercepted and is seeking the release of all its passengers, who include 28 activists and two freelance journalists.

Greenpeace says the activists had been engaged in a peaceful protest in international waters to highlight the environmental risks posed by drilling in Arctic waters.

The group says Russian officials boarded its icebreaker and detained activists at gunpoint after the group piloted motorboats toward an exploration vessel working for Russia's top oil producer, the state-controlled Rosneft, and global major ExxonMobil.

Two activists also scaled the side of the Gazprom-owned Prirazlomnaya platform, actions Russia's Foreign Ministry said threatened security.

As well as the Dutch citizens, the group includes six Britons, four Russians, two Argentines, two Canadians, two New Zealanders, a man with Swedish and US citizenship and one national each from the United States, Australia, Brazil, Denmark, Finland, France, Italy, Poland, Switzerland, Turkey and Ukraine.

The activists are currently being held in custody in the northern Russian city of Murmansk.