A man holds a laptop computer as cyber code is projected on him in this illustration picture taken on May 13, 2017. 鈥 REUTERS

听–听Beijing-linked听丑补肠办别谤蝉听accessed US Ambassador to China Nicholas Burns’ email account in an espionage operation thought to have compromised at least hundreds of thousands of individual US government听别尘补颈濒蝉, the Wall Street Journal (WSJ)听聽on Thursday.

Daniel Kritenbrink, the assistant secretary of state for East Asia, was also hacked in the wider spying operation disclosed earlier this month by Microsoft, the report said, citing people familiar with the matter.

Asked about the reported听产谤别补肠丑听of the two diplomats’ accounts, the State Department declined to give any details and said its investigation of the spying operation was ongoing.

Before the听奥厂闯听report appeared, Mr. Kritenbrink was asked at a congressional hearing on US China policy whether he could rule out that his or his staff’s听别尘补颈濒蝉聽were targeted in the Microsoft hack.

I can’t comment on an investigation that’s underway being conducted by the FBI, but no, I will not rule it out,” Mr. Kritenbrink said.

Mr. Burns and Mr. Kritenbrink join US Commerce Secretary 聽as the only publicly named victims of the espionage campaign, which prompted a warning by Washington’s top diplomat to his听颁丑颈苍别蝉别听counterpart.

“China firmly opposes and combats cyber attacks and cyber theft in all forms. This position is consistent and clear,” Liu Pengyu, spokesperson for China’s embassy in Washington, said in an emailed response to Reuters.

“Identifying the source of cyber attacks is a complex technical issue. We hope that relevant sides will adopt a professional and responsible attitude … rather than make groundless speculations and allegations.”

Microsoft said last week that听颁丑颈苍别蝉别听丑补肠办别谤蝉听misappropriated one of its聽听补苍诲听耻蝉ed a flaw in its code to steal听别尘补颈濒蝉聽from US government agencies and other clients.

The company did not immediately return a message seeking comment on the听奥厂闯听report.

The听产谤别补肠丑听has thrown Microsoft’s security practices under scrutiny, with officials and lawmakers calling on the Redmond, Washington-based company to make its top level of digital auditing, also called logging, available to all its customers free of charge.

Microsoft said in a statement late on Thursday that it was taking the criticism on board.

Last week, White House National Security Council spokesperson Adam Hodge said an intrusion in Microsoft’s cloud security “affected unclassified systems,” without elaborating.

“Officials immediately contacted Microsoft to find the source and vulnerability in their cloud service,” Mr. Hodge added.

The State Department “detected anomalo耻蝉听activity” and “took immediate steps to secure our systems,” a department spokesperson said in a statement at the time. – Reuters