New Delhi, June 14: India remained the world's second-largest buyer of Russian fossil fuels in May, importing an estimated 5.8 billion euros (USD 6.7 billion) worth of Russian hydrocarbons as refiners stepped up crude purchases from Moscow, European think tank Centre for Research on Energy and Clean Air (CREA) said in a report. Crude oil accounted for about 83 per cent of India's imports from Russia during the month, valued at 4.8 billion euros, while oil products and coal imports stood at 550 million euros and 429 million euros, respectively. "India's total crude import volumes recorded an 8 per cent month-on-month increase in May.