U.S. crude futures hit a two and half year high, today, on concern that violence in Libya could cut more of the OPEC-member's output, and that a similar story could play out in other top oil producers in North Africa and West Asia. As deadly clashes wracked Libya's biggest cities, one international oil firm shut down as much as 100,000 barrels per day of output, or about 6 percent of output in Africa's third-largest producer. So U.S. crude for March delivery touched its highest level since October 2008, at 94.49 dollars a barrel. Brent crude for April delivery rose as high as 108.18 dollars a barrel.