TWO deep-diving Russian mini-submarines descended more than 4km under North Pole ice to stake a flag on the ocean floor yesterday, as part of a quest to bolster Russian claims to much of the Arctic’s oil-and-mineral wealth.

Two deep-diving Russian miniature submarines today descended more than two and a half miles to the ocean floor beneath the North Pole, the ITAR-Tass news agency reported.

One of Russia’s two deep-diving miniature submarines today began its descent more than two-and-a-half miles beneath the ice to the ocean floor beneath the North Pole, RTR television reported.