The rise in crude stocks reversed a 2 percent fall in February and was equivalent to a stock-build of about 130,000 barrels per day, according to Reuters calculations based on previous data from the newsletter, Xinhua Oil, Gas and Petrochemicals (OGP).

That implies non-commercial reserves of crude oil grew by about 165,000 bpd, according to a Reuters calculation based on the OGP figures and other official data.

Among the fuels, diesel stocks fell hardest, down 12 percent, while kerosene stocks declined 8.5 percent and gasoline was down 1.4 percent.

China's diesel stocks had built strongly from about 6.25 million tonnes in October and stood at around 10.3 million tonnes at the end of March, according to Reuters calculations based on sporadic publication of absolute figures in OGP.