Indian government bonds tumbled on Friday, with the benchmark yield posting its biggest weekly rise in eight weeks, as oil prices spiked and the lack of clarity on an index inclusion announcement prompted traders to cut risk before the weekend.The ‌benchmark 6.94% 2036 ⁠bond ⁠yield ended at 6.7799%, up from Thursday's close of 6.7478%. It rose 6.5 ​basis points this week, after staying range-bound last week and declining in the previous ​six.Bond yields move inversely to prices.India bonds sink on oil spike, index-entry uncertaintyOn Friday, Indian government bonds underwent a notable drop, with benchmark yields marking the steepest weekly rise in the past eight weeks. The surge in oil prices and concerns over index inclusion led traders to exercise caution, reducing their risk exposure as they approached the weekend. This trend is indicative of wider economic challenges affecting global markets.Brent crude futures jumped nearly 2% on Friday to $86 per barrel, taking their weekly rise to about 13%, as fighting between U.S. and Iran intensified, ⁠disrupting oil ‌traffic through the Strait of Hormuz. For India, the world's third-largest oil importer, higher crude prices can pressure the rupee, ⁠widen the import bill and stretch government finances.Fears of ​higher U.S. rates also weighed on emerging-market bonds earlier ​in the week, though softer U.S. inflation and PPI data helped scale back rate-hike bets.This helped preserve the yield advantage of EM local-currency bonds, HSBC said in a note.Foreign demand for Indian bonds remained firm, with overseas investors net buying about 16.5 billion ‌rupees of bonds under the fully accessible route from Monday to Thursday amid expectations of possible inclusion in Bloomberg's ​index. "Traders cut ​holdings in a ⁠risk-off move on Friday as crude climbed further, and in the absence of news on index inclusion, the selling could continue next week," a ​trader at a primary dealership said.RATESIndia's overnight index swap rates rose as traders pared risk before the weekend.The one-year rate was up 3.25 bps at 5.9275%, the two-year rose 1.75 bps to 6.0850%, and the five-year climbed 3.75 bps to 6.3775%.