By Noah Browning LONDON/HOUSTON (Reuters) -Oil prices rose on Monday over the stand-off between Russia and the West over Ukraine, adding to supply concerns that have kept oil prices near $100 a barrel. Brent crude futures jumped $2.74, or 2.91%, to $96.28 a barrel by 2 p.m. ET (1910 GMT). U.S. West Texas Intermediate (WTI) crude futures rose $2.79, or 3,06%, to $93.86 a barrel at 1915 GMT. Russian forces killed a group of five saboteurs who breached the country’s southwest border from Ukraine on Monday, news agencies quoted the military as saying, an accusation that Ukraine called fake news. F…