By Alexander Cornwell

MANAMA, Bahrain (Reuters) – The U.S. believes that an alleged sweeping Chinese cyber espionage campaign known as Salt Typhoon targeted and recorded telephone calls of “very senior” American political figures, a White House official said on Saturday.

The comments by Anne Neuberger, the U.S. deputy national security advisor for cyber and emerging technology, to reporters at the Manama Dialogue regional security conference in Bahrain’s capital revealed new details of the campaign.

While a large number of Americans’ metadata likely has been stolen, U.S. officials understand that “the purpose of the operation was more focused,” Neuberger said.

“We believe … the actual number of calls that they took, recorded and took, was really more focused on very senior political individuals,” she continued.

She did not elaborate, including revealing the identities of those who were targeted.

Chinese officials previously have described the allegations as disinformation and said that Beijing “firmly opposes and combats cyber attacks and cyber theft in all forms.”

“We’re still investigating the scope and scale” of the hacking campaign, Neuberger said.

The New York Times (NYSE:) in October reported that members of U.S. President-elect Donald Trump’s family and Biden administration officials were among those targeted by China-linked hackers who broke into telecommunications companies.

A senior U.S. official this week said dozens of companies worldwide have been struck by the hackers, including at least eight telecommunications and telecom infrastructure firms in the U.S.

U.S. officials have alleged the hackers’ targets included Verizon (NYSE:), AT&T (NYSE:), T-Mobile, Lumen, and others and that telephone audio intercepts along with a large tranche of call record data were stolen.