Russia's emergency services rescued 536 ice fishermen after they got stranded on a giant ice floe that broke off the island of Sakhalin in eastern Siberia, officials say. Around 60 more people were able to get back on the shore on their own Tuesday evening, emergency officials said. The rescue operation lasted for almost seven hours. Footage of the incident showed groups of people using smaller pieces of ice as rafts and trying to row to the coast on them, as the ice floe with stranded fishermen slowly drifted further away from the land, the AP reports. It is the third time in a week that emergency services in the Sakhalin region have had to rescue ice fishermen stuck on drifting glacial masses. Local authorities blamed the incidents on fishermen ignoring safety warnings and going ice fishing despite the danger of being stranded on ice floes. (More Russia stories.)