Government officials were told on Friday that experts studying the mysterious illnesses affecting dozens of diplomats, spies and their families are striving to find evidence to support the main theory, that the microwave attacks are launched by Russian agents, the Times reported.

The revelation followed an unusual classified meeting convened by the Director of National Intelligence, Avril D. Haines, to assess investigations and efforts to deal with victims of alleged attacks on State Department officials, C.I.A. officers and their families.

According to reports, the National Security Council initiated an urgent effort to address the issue, and two separate working groups are now in operation, one investigating the cause and led by the C.I.A. and the other focused on finding commercial technology that can detect or block attacks.

The Friday meeting was also attended by Secretary of State Antony Blinken; Attorney General Merrick B. Garland; C.I.A. Director William Burns; and F.B.I. Director Christopher A. Wray.

According to the Times, the attacks, which date back to 2016, went from a medical mystery to an urgent national security issue.

Biden administration officials say they were surprised at how disorganized the government’s response was over the past four years, in part because there was no centralized way for departments to share episode reports.

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