Global oil benchmark Brent on Tuesday rose above $89 a barrel for the first time since October, albeit briefly, as oil supplies faced fresh threats from Ukrainian attacks on Russian energy facilities and escalating conflict in the Middle East.Brent futures for June delivery were up $1.35, or 1.5%, at $88.76 a barrel by 11:40 a.m. EDT (1540 GMT) after touching a peak of $89.08.U.S.