KYIV (Reuters) -Ukraine's SBU security service said on Tuesday that it had hit the road and rail bridge linking Russia and the Crimean peninsula below the water level with explosives. In a statement, the SBU said it had used 1,100 kilograms (2,420 pounds) of explosives that were detonated early in the morning and damaged underwater pillars of the bridge, a key supply route for Russian forces in Ukraine in the past.