Russia’s exports to China dropped by almost a third in the first six weeks of the year as the spread of coronavirus sapped demand in the world’s second-biggest economy.

Exports dropped 21% to 620,000 tons year-on-year in January and halved to 118,000 tons in the first 10 days of February, the Izvestia newspaper reported Wednesday, citing data from the Far East unit of the Russian Customs Service. The biggest declines were in minerals, timber and other raw materials, the data show. The report didn’t include dollar values for the trade and the agency couldn’t immediately provide figures.

Russia is especially vulnerable to an extended shutdown in China because of President Vladimir Putin’s push to re-orient the economy eastward since the onslaught of Western sanctions in 2014. A possible dent in growth would come just as Putin is trying to boost spending to spur the economy after years of stagnation.

“A slowdown in the Chinese economy is a serious risk to Russian trade,” said Tatiana Evdokimova, chief Russia analyst at Nordea Bank in Moscow. “The longer activity in China remains reduced, the higher the risk of a considerable interruption in logistics chains and production that won’t be recuperated in following quarters.”

China is Russia’s biggest trading partner, with bilateral commerce totaling about $110 billion in 2018, according to data compiled by Bloomberg. While the Russian economy has also been hit by a slump in global oil prices due to a drop in demand, the data don’t show a decrease in crude exports to China since the beginning of the year.