The World Bank warned that rising capital flows to East Asia are fanning fears of asset bubbles and authorities need to be careful not to repeat the mistakes of the Asian financial crisis more than a decade ago.

Asian currencies are appreciating as low yields in developed countries drive capital into the region, the development lender said on Tuesday. This could fan inflation, lead to asset bubbles and harm the banking sector.

"Larger inflows combined with ample domestic liquidity and rising confidence have boosted stock markets, real estate prices and other asset valuations in some countries, precipitating fears of a new bubble," the report said.

"The authorities in East Asia need to take adequate precautions to ensure that they do not repeat the same mistake twice in slightly over a decade."

Intervention to slow currency gains has had limited success and uncoordinated intervention is only adding to global liquidity, the World Bank said.

It added that capital controls were not very effective in controlling long-term investment flows.

Group of 20 finance ministers, meeting in South Korea on Friday, will grapple with the global currency system as developed and emerging countries trade barbs over competitive devaluation.   

Asian countries have a mix of instruments available to deal with rising inflows, such as adjusting monetary policy, withdrawing stimulus and regulating the banking sector to prevent careless borrowing and lending, Vikram Nehru, the World Bank's chief economist for Asia-Pacific, told reporters on Tuesday.

There is some evidence that capital flows to East Asia are becoming more short-term, Nehru said, but he was confident that Asian governments would not allow inflows to become so short-term that they could reverse quickly, as they did in the 1997 Asian financial crisis.

"We are seeing an effort by developing East Asia to deal with the large amounts of liquidity driven in very large part by the monetary policy easing in the United States," Nehru said. "If this liquidity abundance is sustained and increases, I think they are going have to take further action."    

Policymakers need to be careful that unsterilised currency intervention does not lead to inflation, he added, as it would increase the money supply. -Reuters