BEIJING, June 2 (Xinhua) -- China's index of export container transport costs continued to rise during the past week as stable growth in demand drove up prices, according to the Shanghai Shipping Exchange.

The average China Containerized Freight Index (CCFI) stood at 1,495.98 on May 31, up 7.7 percent from a week earlier, the exchange revealed.

The index has been climbing since the beginning of May, with freight rates for the South American, African and Persian Gulf and Red Sea shipping routes leading the gains, which Hua Chuang Securities analysts have attributed to geopolitical tensions and improving export demand.

Domestic manufacturers rushing to ship goods ahead of the imposition of higher tariffs, such as Brazil's planned import tax hikes on electric vehicles in July in particular, also helped boost shipping demand and push up prices, said Zhang Yu, chief analyst at Hua Chuang Securities.

The CCFI tracks spot and contractual freight rates from Chinese container ports for 12 shipping routes across the globe, based on data from 24 international carriers.

A breakdown of the May 31 reading showed that the sub-reading for the West and East Africa service had led the increases with week-on-week growth of 16.9 percent, followed by that for the South Africa route, which rose by 10.9 percent from the previous week.