Indian bond yields surged the most in nearly 30 months and ended at their highest since January last year, with an unprecedented spike in crude oil prices and the likelihood of fuel-stoked inflation increasing the probability of policy rate hardening by global central banks. Yield on the 10-year benchmark government bond jumped 10 basis points to close at 6.83%, CCIL data showed. One basis point is a hundredth of a percentage point. The 10-year yield opened at 6.78% and inched up to 6.88% in the first hour of the session as global markets traded with nervousness ahead of the expiry of Donald Trump's 48-hour deadline to Tehran to reopen the Strait of Hormuz.