Two Japanese citizens arrested in China on suspicion of spying may have been collecting information about Chinese military activities and North Korea for the Public Security Intelligence Agency, a Japanese government source said Friday.

According to Japanese and Chinese diplomatic sources, the two men suggested that they had entered the country to collect information at the request of the Japanese intelligence agency, which is in charge of gathering and analyzing information on threats to national security and public safety.

The two individuals, detained in May, are civilians, the diplomatic sources said.