Suspected Chinese hackers tried to steal the passwords of hundreds of Google Inc. email account holders, including those of senior U.S. government officials, Chinese activists and journalists, Reuters reported.

Google’s claim sparked an angry response from Beijing, which said blaming China was “unacceptable,” pointing to further tensions in an already strained relationship with Google.

The perpetrators appeared to originate in Jinan, the capital of China’s eastern Shandong province, Google said. Jinan is home to one of six technical reconnaissance bureaus belonging to the People’s Liberation Army and a technical college U.S. investigators last year linked to a previous attack on Google.

The FBI said it was working with Google following the attacks.

The hackers tried to crack and monitor email accounts by stealing passwords, but Google detected and “disrupted” their campaign, the company said on its official blog. Google said it had notified the victims.

The revelation comes more than a year after Google disclosed a cyberattack on its systems that it said it traced to China. Google partially pulled out of China, the world’s largest Internet market by users, last year after a tussle with the government over censorship.