Russian President Vladimir Putin stressed that his country has stepped up security and is prepared to handle any threats.
But some U.S. lawmakers -- and at least one Olympic athlete -- have said they're worried about the situation.
Police in Sochi have handed out fliers at area hotels warning of a woman they believe could be a terrorist and who may currently be in the city.
One flier, obtained by CNN, asks workers to be on the lookout for Ruzanna "Salima" Ibragimova, described as the widow of a member of a militant group from the Caucasus region.
The woman, according to the flier, may be involved in organizing "a terrorist act within the 2014 Olympic region."
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