The allegations made by two former military intercept officers with the National Security Agency include claims that U.S. intelligence officials routinely listened in on personal conversations and sometimes shared the recordings, The Washington Post reported. The accusers said spies eavesdropped on aid workers and U.S. military personnel talking to families.

Senate Intelligence Committee Chairman John D. Rockefeller IV, D-W.Va., called the accusations "extremely disturbing" and said his staff has begun information-gathering and he's considering holding hearings.

"Any time there is an allegation regarding abuse of the privacy and civil liberties of Americans, it is a very serious matter," Rockefeller told the Post.

The two former officers said in interviews Thursday the NSA's intercept program was intended to gather intelligence about terrorists and their plans, but that operators also would tap into phone calls by Americans living abroad.

While not providing specifics, an NSA spokesman said some of the allegations were being investigated while others weren't substantiated.