The 30 Greenpeace activists arrested by Russian authorities over a protest against its Arctic oil drilling were shifted from the northern city of Murmansk to pre-trial detention centers in St. Petersburg Monday.

A passenger train starts, with a green carriage which is believed to transport 30 people who were arrested over a Greenpeace protest at the Prirazlomnaya oil rig seen in the train formation, in Murmansk on the way to St. Petersburg, November 11, 2013. Thirty people arrested in Russia over a protest against Arctic oil drilling were moved from the northern city of Murmansk on Monday on their way to pre-trial detention centres in St. Petersburg, federal investigators and Greenpeace said. The transfer, which follows a reduction of the charges against 28 activists and two journalists, may be aimed to curb international criticism of Russia over what the environmental group says was a peaceful protest. (REUTERS/Dmitri Sharomov/Greenpeace/Handout via Reuters)

Shifting of the detainees was seen as an effort by Russia to curb international criticism of its handling of what the environmental group claimed as a peaceful protest. Earlier reports noted the activists were being confined for 23 hours a day in bleak and at times ice-cold cells in Murmansk, which is a port city of Russia above the Arctic Circle. The remote location had complicated access for lawyers and consular officials to meet the arrested activists.

"St. Petersburg has some daylight in the winter months, unlike Murmansk," Ben Ayliffe, an Arctic campaigner for Greenpeace, was quoted by Reuters. The shifting, however, did not guarantee better conditions, the campaigner said.

Families of the detained activities are hoping that the transfer from the isolated Arctic port of Murmansk to St Petersburg, which is Russia's second-largest city, would allow the detainees greater access to consular officials and lawyers.

Russia has charged with hooliganism and facing up to seven years in prison if convicted, they had been denied bail and held in pre-trial detention in Murmansk, 1,000 kilometers (640 miles) north of St. Petersburg.

The 28 Greenpeace activists and two journalists were arrested on Sep. 8 and their vessel detained after Russian coastguards boarded the Greenpeace icebreaker vessel "Arctic Sunrise" following a protest by the environmental group at a Russian oil platform owned by state-controlled Gazprom off the country's northern coast.

Russia held the environmental activists guilty after violating the law in the protest in which some of the members tried to scale the Prirazlomnaya platform.

Russian authorities have withstood international pressure to release the activists. The country refused to participate in a case filed by Netherlands at the International Tribunal for the Law of the Sea. Two of the activists were Dutch citizens and the Greenpeace vessel, "Arctic Sunrise," was Dutch-registered.