I was wrong about the dates. Those articles are saying that in June foreign purchases of US debt surged -- the month the OP says was lower.
I think that the BBC article about reductions and the other articles about increases are about offsetting or different transactions. The simplest explanation is that China dumped some of its "holdings" but purchased newly issued securities. That would make sense if they had purchased very low interest short term debt the Treasury was offering during the financial crisis, and turned around and purchased higher interest long term securities that the Treasury is now offering. Then again maybe China was dumping securities and the Treasury panicked and put out a happy news story. Hard to tell, but compare:
http://news.bbc.co.uk/2/hi/business/8207174.stmChina reduces holdings in US debt
Dollar notes
China wants to establish a new global currency regime
China reduced its holdings of US government debt by the largest margin in nearly nine years in June, according to data from the US Treasury.
http://www.google.com/hostednews/afp/article/ALeqM5jkLPvWOBY92j4XQTNARw05LkU2xwForeign purchase of US securities surge
By P. Parameswaran (AFP) – 2 days ago
WASHINGTON — Foreign purchases of US long-term securities surged in June, reversing an outflow the previous month and signaling recovery of battered financial markets, new data showed Monday.
The jump was primarily driven by a sharp increase in overseas demand for long-term US Treasury securities, including from China, the biggest owner of American debt, according to the monthly US Treasury international capital report.
It said that net long-term security transactions in June climbed to 90.7 billion dollars from negative 19.4 billion dollars in May as both private and official foreign investors beefed up their portfolios.
The June figure was substantially higher than market expectations of 17.5 billion dollars.
Analysts said the fresh data underscored a recovery in financial markets reeling from a prolonged US recession and signaled that the underlying demand for US securities remained healthy.
"This provides further support to the view that financial markets are on the road back to normalcy," said Bodhi Ganguli, an economist at Moody's Economy.com.