China was a heavy seller of US Treasury debt in August after Standard and Poor’s downgraded the country’s triple A credit rating, according to monthly data released on Tuesday by the Treasury.

But foreign demand for US stocks, bonds and other financial assets surged in August as investors focused on buying Treasuries as a haven investment. The eurozone debt crisis and a sharp fall in global equities outweighed any impact on demand from S&P cutting the US credit rating one notch to double A+ in early August. Large purchases of US Treasury securities came from investors in the UK, Switzerland, Japan and Caribbean banking sectors, which are favoured by hedge funds.

“The flows reinforce the safe-haven appeal that US Treasuries continue to enjoy, even if the turmoil was being driven in part by concerns about the quality of these assets,” said Millan Mulraine, analysts at TD Securities.