Democratic Republic of Congo's oil ministry has called for bids to exploit reserves of methane gas at the bottom of Lake Kivu on its eastern border with Rwanda, the prime minister's office said on Friday. The office announced the tender on its twitter account but did not give details. An oil ministry official said the tender process had not yet begun but added that Congo needed the gas to help meet its energy deficit. "It is very important that we exploit this gas, because otherwise it has the potential to explode and cause significant damage to the population," said the ministry official, who requested anonymity. Methane and carbon dioxide collect at the bottom of the lake's icy waters.