Moscow, Sep 26 (IANS): Thirty Greenpeace members would remain in police custody in the Russian city of Murmansk for 48 hours while their protest actions were being investigated, authorities said Wednesday, Xinhua reported.

The activists were aboard the Greenpeace vessel Arctic Sunrise, which Russian border guards escorted to the White Sea port Tuesday.

"Eight people are (being held) in the Leninsky district, nine are in the Oktyabrsky district, the location of the others is currently unknown. We are looking for them," Irina Paikacheva, head of a Murmansk regional human rights commission, told the Interfax news agency.

Lawyers for the environment group have rushed to the city to assist the detainees, who were arrested Sep 18-19 while attempting to stage a protest against oil extraction on the Prirazlomnaya oil platform in Russia's exclusive economic zone.

The Russian investigative committee has opened a criminal inquiry into the incident. Three of the detained activists are Russian citizens, committee spokesperson Vladimir Markin said.

Russian President Vladimir Putin said Wednesday the activists were not pirates and Moscow intended to cooperate with all parties and environmental organisations "but this work should be civilised".

However, he said the activists had breached international legal norms.

Russia's Human Rights Commissioner Vladimir Lukin Tuesday called for leniency for the detained activists, saying, though their actions were "eccentric", the activists had "admirable and noble motives".

However, Markin said the circumstances and motives of the Arctic Sunrise crew and their actions would be determined during the investigation, which involved 16 investigators.