Russian scientists say they've set a new record by diving to the bottom of one of the deepest lakes in the world.
Two mini-submarines travelled 1,680-metres to reach the bottom of Russia's Lake Baikal in Siberia, which holds one fifth of the world's fresh water.
The team is waiting for confirmation that they've set a new world record for the deepest dive in fresh water.
Scientists are working in the lake on a two-year mission to find out more about the lake's underwater world.
The Mir I and Mir II mini-submarines which touched the bottom of the lake are already in the record books for reaching depths of more than 4,000m on a separate expedition.