Environmental group Greenpeace declared that it will appeal the rulings of a Russian court that jailed 28 of its activists for protesting at an Arctic oil platform.

On Thursday a court in Murmansk jailed the activists along with a freelance Russian photographer and a freelance British videographer after a protest near the platform owned by Russian state energy giant Gazprom.

Greenpeace said that it was seeking the crew's immediate release.

"These detentions are like the Russian oil industry itself, a relic from an earlier era," said Greenpeace International executive director Kumi Naidoo. "Our peaceful activists are in prison tonight for shining a light on Gazprom's recklessness.

"The Arctic is melting before our eyes and these brave activists stand in defiance of those who wish to exploit the developing crisis to drill for more oil."

Of the 30 people jailed, 22 were remanded in custody for two months pending inquiries and the other eight were detained until a Monday hearing.

No charges have been brought against any detainees.

Reporters Without Borders protested over the jailing of freelance photographer Denis Sinyakov, saying that his arrest was "an unacceptable violation of freedom of information."

The Organisation for Security and Co-operation in Europe also demanded Mr Sinyakov's immediate release.

Several Russian news websites blacked out their photographs yesterday in protest at the detention of Mr Sinyakov.