Officials with the U.S. Centers for Disease Control and Prevention said Sunday they were responding to the Ebola outbreak in the Democratic Republic of Congo and Uganda. File Photo by Erik S. Lesser/EPA-EFE

May 17 (UPI) -- The U.S. Centers for Disease Control and Prevention's offices in the Democratic Republic of Congo and Uganda are responding to the Ebola outbreak, federal health officials said Sunday, amid reports that Americans have been exposed to cases in the DRC.

It was not clear how many Americans were affected by the outbreak, but CBS News, citing unnamed sources at an international aid organization, reported at least six Americans were exposed to the virus, including three considered to have experienced high-risk contact or exposure.

U.S. health news organization STAT was the first to report on Sunday that Americans were involved in the outbreak, stating a number of Americans are believed to have been exposed to suspected cases in the DRC, with several deemed high-risk.

When asked about the reported exposures during a CDC press conference on Sunday, Dr. Satish Pillai, the agency's Ebola response incident manager, said the agency doesn't comment on "individual dispositions."