China's commercial crude oil inventories at the end of May rose 4 per cent from a month earlier as crude imports remained high, the official Xinhua news agency said. But refined fuel stocks fell 5.48 per cent from end-April, Xinhua reported in its oil and gas newsletter China OGP. Of the total, diesel stocks slumped 11.4 per cent, gasoline stocks rose 0.93 per cent and kerosene stocks increased 0.16 per cent, it said.The fall in diesel stocks came as industrial activity accelerated and the summer harvest started in May. Factory output rose 8.8 per cent in May from a year earlier, in line with market expectations and quickening slightly from April's 8.7 per cent pace, official data has shown.The OGP newsletter does not provide outright inventory volumes, and the government rarely discloses levels of either commercial or strategic oil stocks, making it difficult to gauge real demand in the world's second-largest oil consumer. China imported 6.14 million barrels per day (bpd) of crude oil in May, up 8.9 per cent from a year earlier, although it was down 9.4 per cent from a record high of 6.78 mbpd in April.China's refinery crude throughput in May rose 3.5 per cent from a year earlier to 9.5 mbpd, official data has shown. But daily crude runs were down from 9.63 mbpd in April, as refineries scaled back output amid peak maintenance period.