China imported 32.17 million mt of iron ore from Australia in March, up 12% year on year and up 27.5% from February, data released Wednesday by the General Administration of Customs showed.

Australia remained the top supplier of iron ore to China, accounting for 50% of total imports in March, compared with 45% in February.

Imports from Brazil, China's second largest iron ore supplier, totaled 11.77 million mt in March, down 4.7% year on year and down 14% month on month, the data showed. A trading source attributed the decline to production issues in Brazil.

China, the world's largest importer of iron ore, imported a total of 64.55 million mt in March, up 2.7% year on year and up 14.4% from February, the General Administration of Customs said earlier this month. It releases a preliminary monthly total early the following month, and a breakdown several weeks later.

A Singapore-based trader said the pickup in demand for Australian iron ore in March was due to Chinese mills ramping up crude steel production in anticipation of stronger demand in April.

"April is the peak period for construction activity in China and we are seeing more demand for mainstream iron ore from Australia as many mills are increasing their production to meet stronger demand," the trader said.

China produced 66.3 million mt of crude steel in March, up 7% from February, according to National Bureau of Statistics data released earlier.

The country's iron ore imports from India totaled 1.11 million mt in March, down 76% year on year and up 92% from February.

"We might be seeing more Indian ore being offered in the spot market now as we received news [Tuesday] that a slow release of some miners from the current mining ban in Goa is taking place," a Shanghai-based trader said.

China's imports from India have declined since New Delhi hiked export duties to 30% from 20% on December 30, 2011, while a ban on mining in the states of Karnataka since August 2011 and Goa since September 2012 have limited availability.