HONG KONG — China has acknowledged for the first time that the breach of the United States Office of Personnel Management’s computer systems, which the Obama administration said exposed the personal information of more than 21.5 million people, was the work of Chinese hackers. But China insisted that the breach was the result of criminal activity, not a state-sponsored cyberattack.

The assertion came in one paragraph midway through an article published Tuesday by Xinhua, the state-run news agency, about a meeting in Washington between top Chinese and American law enforcement officials, and it raised more questions than it answered.

The session was the first since President Obama and President Xi Jinping of China announced a set of vague rules of the road about what kind of hacking is impermissible. The two countries have promised to work toward a more comprehensive understanding.

The report did not say whether the Chinese authorities had identified anyone suspected of carrying out the immense breach of security, which was revealed this year.