Russia and Norway signed an accord on Friday committing them immediately to alert their neighbor of any sea accidents such as the underwater explosion that sank a Russian submarine last month. Russian Prime Minister Mikhail Kasyanov and his Norwegian counterpart Jens Stoltenberg signed a memorandum in Oslo, which also included a plan to start joint search and rescue exercises. "We agree that we will expand, tighten and strengthen the duty to give the alert about accidents at sea," Stoltenberg was reported as saying at a joint news conference in Oslo after meetings with Kasyanov. Norwegian divers helped Russia in its rescue work after the Kursk submarine sank in the Arctic Barents Sea about 150 miles from NATO-member Norway, killing all 118 onboard.