MOSCOW, June 19 (RIA Novosti) - Explorers conducting mini-submarine dives in Siberia's Lake Baikal began their search on Friday for several carriages known to have sunk in the world's deepest lake during the 1917-1923 Russian Civil War.

A member of the expedition told RIA Novosti that the Mir-2 submersible spent five hours under water on Friday morning, reaching a depth of 1,121 meters near Cape Polovinny.

"The apparatus has been lifted to the tug-boat base, where we are waiting for the results of the dive," he said.

Divers earlier discovered carriage wheels dating back to the civil war, at a depth of 70 meters near the cape. The carriages themselves are believed to be at a greater depth.

The main focus of the ongoing expedition involving the Mir-1 and Mir-2 submersibles, which resumed on Monday following last summer's 52 dives, is on scientific research rather than artifact hunting.

During a dive on Thursday, explorers recovered a sensing device left in the lake during last summer's exploration work. A sensor was dropped in the southern part of the lake a year ago to monitor temperature, salinity, and oxygen and water-transparency levels.

During the second phase of research, the expedition will explore underwater methane hydrates, mud volcanoes, and the organisms living in the lake. Ecological research will also be conducted into the impact of the toxic waste released by the now-closed Baikal pulp and paper mill from the 1960s onwards.

Lake Baikal has a coastline of over 2,000 km and a maximum depth of 1,637 meters. The UNESCO world heritage site contains 83% of Russia's and 20% of the world's unfrozen freshwater.