Russia on Thursday released 10 Greenpeace activists on bail, bringing to 11 the number freed from jail as President Vladimir Putin said the group had noble motives for their Arctic protest.

The activists who walked free from prison included Russian freelance photographer Denis Sinyakov, Greenpeace press secretary Andrei Allakhverdov and Finnish activist Sini Saarela, who was one of those to scale a state-owned oil platform.

Their release came after Greenpeace paid bail of two million rubles ($60,750) each. The first activist to be freed was Brazil's Ana Paul Maciel on Wednesday.

Putin said he believed the Greenpeace activists were acting with good intentions, but that they were wrong to climb up the oil platform and ram the boats of coastguards.

"Are they doing something noble? Yes, they are. Did they act rightly when they climbed the platform? No, it was not right," he said in televised comments at a meeting with writers.

"Some climbed onto the platform, while others attacked our coastguards, practically storming them with their boats," Putin said.

Putin quoted a catch phrase from a 1960s-era Soviet comedy film referring to physical punishment: "Fedya, that's not our method."

After treating the 30 crewmembers harshly on their arrest, the Russian authorities have gradually climbed down, reducing their charge from piracy to hooliganism and now sanctioning their release.

On Thursday, courts granted bail to six more activists: Jon Beauchamp of New Zealand, British crewmembers Frank Hewetson and Iain Rogers, Ukrainian cook Ruslan Yakushev, Canadian bosun Alexandre Paul and Turkish activist Gizem Akhan, Greenpeace said.

Fifteen activists were now awaiting release on bail, while one Australian activist had bail refused. The last three activists are scheduled to attend court hearings on Friday.

But the activists still face a possible jail sentence of up to seven years.

'An act of protest is not hooliganism'

Sinyakov's detention over the September protest at a state-owned oil rig was particularly controversial because he is a well-known press photographer who was working for Greenpeace as a freelancer.

The photographer, who has grown a beard in prison, raised a fist in triumph after stepping out of the notorious Kresty prison.

"An act of protest is not hooliganism," Sinyakov told TV Rain.

"My main task is to prove my innocence.I will be trying to achieve that."

He said that the conditions in the Murmansk prison where he was held until this month were much worse than those in Saint Petersburg, but "they were bearable."

"The psychological situation itself is harder," he said.

On Wednesday evening, the first Greenpeace activist, Maciel, walked out of prison, smiling and holding a sign saying "Save the Arctic".

"Ana Paula's passport has now been given back to her and she has been given a special registration card stating that she legally arrived in the Russian Federation," Greenpeace said in a statement sent to AFP, adding that all the freed activists were staying in Saint Petersburg.

"There is no clarity on when the Arctic 30 will be able to return home."

Sinyakov told TV Rain that the investigators were still holding his international passport.

The jailing of the 30 activists prompted calls for their release from politicians including British Prime Minister David Cameron as well as pop stars such as Madonna and Paul McCartney.

A court refused bail to 59-year-old Australian radio operator Colin Russell, extending his detention until February 24.

Australia's ambassador to Russia, Paul Myler, wrote on Twitter that he visited Russell Thursday and the activist was "in good spirits and confident his appeal will be successful."

Myler said Russian officials had suggested to him that Russell could have been denied bail simply because he was the first activist in court.

"General consensus: the first pancake never works out," Myler wrote, a Russian proverb meaning that the first attempt at something is usually unsuccessful.

Those granted bail include the two activists who scaled the oil rig during the September 18 protest in the Barents Sea.

Greenpeace said Thursday that a court in Murmansk rejected the group's appeal against the confiscation of their ship.