BEIJING/SINGAPORE - China's March crude oil imports from top supplier Saudi Arabia fell 1.6% from a year earlier, while purchases from No.2 supplier Russia rose 31%, Reuters' calculations based on customs data showed on Sunday.

China's March crude oil imports rose 4.5% year on year to 9.68 million barrels per day (bpd) as refiners stocked up on cheaper cargoes despite falling domestic fuel demand and cuts in refining rates due to the impact the COVID-19 pandemic.

Shipments from Saudi Arabia were 7.21 million tonnes, or 1.7 million bpd, data from the General Administration of Customs showed.

That was down from 1.73 million bpd a year earlier and average daily imports of 1.79 million bpd during the first two months of this year.

Russia supplied 7.02 million tonnes last month, or 1.66 million bpd, down from 1.71 million bpd recorded for the first two months, the data showed.

While state refiners mostly maintained deep production cuts in March to reduce their fuel stocks, independent plants cranked up run rates as the oil price plunge triggered partly by Saudi and Russian pledges to increase supply boosted refining margins.

Saudi Arabia and other members of the Organization of the Petroleum Exporting Countries as well as other producers have since reached a new agreement on output cuts, helping to lift oil prices off historical lows but with many saying that deeper reductions will be needed.

China's imports from the United States remained close to zero in March. After falling last year because of the U.S.-China trade war, they are expected to pick up later in 2020 after Beijing started granting tariff waivers on U.S. goods including crude oil from early March.

There were no shipments from Venezuela for a fifth month in a row, as China National Petroleum Corp (CNPC) , Caracas's top oil client, steered clear of Venezuelan crudes to avoid violating secondary U.S. sanctions.

Also, data showed China's imports from Iran at 255,779 tonnes, down 88.9% from a year earlier.

Below are details of imports from China's key suppliers. Volumes are in million tonnes, with the percentage changes calculated by Reuters.

Country March y/y% Jan-March y/y% Saudi Arabia 7.21 -1.6 21.949 15.3 Russia 7.02 31.2 21.073 16.7 Angola 3.99 30.2 10.304 -18.7 Iraq 5.598 45.7 16.222 42.4 Iran 0.256 -88.9 0.922 -84.2 Malaysia 1.054 107 4.634 232 (1 tonne = 7.3 barrels for crude conversion)

(Reporting by Muyu Xu in Beijing and Chen Aizhu in Singapore; editing by Tom Hogue and Jason Neely) ((aizhu.chen@thomsonreuters.com; +65 6870 3284; Reuters Messaging: aizhu.chen.reuters.com@reuters.net))