China's aluminium imports in September rose 2.2% from the previous month, data from the General Administration of Customs showed on Monday, as curbs on domestic production keep demand for overseas metal strong.

Arrivals of unwrought aluminium and products - which include primary metal and unwrought, alloyed aluminium - were 252,921 tonnes last month, up from 247,547 tonnes in August but down 28.9% from a year earlier.

China imported record volumes of aluminium in 2020 as a rapid recovery in Chinese demand - and prices - after the coronavirus outbreak opened up a so-called arbitrage window for cheaper metal to flow in from overseas.

Imports remain high this year as a power supply shortage leads to curbs on energy-intensive aluminium production in China, the world's biggest consumer of the metal. China's primary aluminium output in September fell for a fifth straight month, data released earlier on Monday showed.

January-September imports were up 14.2% year-on-year at 2.275 million tonnes, customs said.

China's imports of bauxite, the main source of aluminium ore, were up 0.3% year-on-year at 8.34 million tonnes in September. That was down 4.1% from August.

(Reporting by Tom Daly, Editing by Louise Heavens) ((; +86 10 5669 2119;))