China confirmed this week that six Japanese nationals were detained for alleged involvement in unspecified “illegal activities.”

The suspects were detained in Shandong and Hainan provinces, a detail highlighted by multiple news source as both locales are home to naval bases. Sources familiar with the matter say the three men detained in Hainan were suspected of posing a threat to national security, according to a report from Nikkei Asian Review.

The confirmation comes as China has made counter-espionage a high-profile priority, and coincides with a New York Times report over the weekend that China killed or imprisoned more than a dozen US CIA sources from 2010-2012.

The Times report included a description of the execution of one source in front of his colleagues in the courtyard of a Chinese government building, which cited three former officials. That account was refuted, citing no sources, by the Chinese Global Times as “a purely fabricated story, most likely a piece of American-style imagination based on ideology.”

The Global Times, however, was willing to accept other details of the New York Times report may have been true, and if so represented a victory for China.

One question worth asking: why is the US intelligence apparatus, along with the New York Times, revealing these old spy stories now?