TOKYO, Jan 28 : Oil prices gained further ground on Wednesday as supply concerns lingered after a winter storm disrupted U.S. crude output and exports, while Middle East tensions lent additional support. Brent crude futures rose 28 cents, or 0.4 per cent, to $67.85 a barrel by 0410 GMT, while U.S. West Texas Intermediate crude climbed 35 cents, or 0.6 per cent, to $62.74 a barrel. Both benchmarks surged about 3 per cent on Tuesday. U.S. producers lost up to 2 million barrels per day or roughly