Updated

Greenpeace on Friday said it would appeal a Russian court decision to detain all 30 crew members of a ship involved in a high seas protest against Arctic oil drilling, including six Britons.

The Lenin district court in the northern city of Murmansk ruled Thursday that 22 crew members will remain in pre-trial detention for two months during the investigation into alleged piracy over the September 18 protest at a Gazprom oil rig.

Six of the activists are British and four Russian, with the rest coming from 16 other countries.

"We will not be intimidated, we will appeal these detentions, and together we will prevail," Greenpeace Executive Director Kumi Naidoo said in a statement.

"These detentions are like the Russian oil industry itself, a relic from an earlier era," he added.

Among those to be held for two months was the ship's American captain, Peter Willcox. He was also the captain of Greenpeace's Rainbow Warrior ship, which French secret services bombed and sunk in New Zealand in 1985.

The court also ordered the two-month detention of photographer Denis Sinyakov, a former staff photographer at AFP and Reuters who was working for Greenpeace as a freelancer.

The other eight of the 30-strong crew of Greenpeace's Arctic Sunrise icebreaker, whose detention was prolonged by three days, face new hearings on Sunday that could see them detained for a further period.

Their cases were postponed because the court lacked information on the activists or could not find interpreters, the Interfax news agency reported.

Greenpeace Russia said on Twitter that the eight had been taken for meetings with investigators on Friday.

The court concluded marathon hearings into the 30 crew members of Greenpeace's ship early on Friday. The activists, 26 of them foreign nationals from 17 different countries, are being held in prisons in the Murmansk region.

'A precedent in Russian journalism'

Russian investigators have accused the Greenpeace activists of piracy after two of them tried to scale state energy giant Gazprom's Prirazlomnaya oil platform in the Barents Sea.

The group has denied committing piracy and accuses Russia of illegally boarding its ship in international waters.

In protest at the detention of photographer Sinyakov, several Russian news websites, including that of NTV national television channel and Novaya Gazeta opposition newspaper blacked out all their photographs on Friday.

"Denis Sinyakov's being accused of piracy and his preliminary detention for two months will probably become a precedent in the history of Russian journalism," Vedomosti business daily warned in an editorial.

Greenpeace said that a British videographer, Kieron Bryan, was also among those detained for two months, as well as support staff including the ship's doctor and cook, who are both Russian.

British second engineer Iain Rogers was also detained for two months, while logistics co-ordinator Frank Hewetson and activist Anthony Perrett, both also Britons, were held for three days pending another hearing.

The court's decision came despite President Vladimir Putin saying on Wednesday that the activists "are not pirates."

Putin added, however, that the activists had broken international law by getting dangerously close to the oil rig.

Putin's spokesman Dmitry Peskov insisted that the president was not involved in the case. "He gave his point of view but from now on the Investigative Committee does its work," Peskov told the Interfax news agency.

Investigators in court said that the activists had committed piracy by trying to seize property with threats of violence.

The spokesman for the Investigative Committee, which probes major cases in Russia, said Thursday that the charge against the group could be reduced in the course of the investigation.

International reaction was muted, with only the Netherlands government on Wednesday calling on Russia to immediately release the detained activists and saying it was considering legal action.

Izvestia daily cited lawyers as saying that Greenpeace's ship could be confiscated under Russian law if it is proven to have sailed into a restricted zone without permission.

The legal situation is unclear since under Russian law, piracy only applies to ships, but under international conventions, it also covers oil rigs, lawyer Konstantin Baranovsky told Kommersant.

Greenpeace held a similar protest at the same oil platform last year without incurring any punishment.