Sen. Chris Murphy (D-Conn.) condemned Russian separatists in Ukraine Saturday for their apparent meddling with the site where Malaysia Airlines Flight 17 went down.
"All you need to know about the character of Ukranian rebels is the disgraceful way they are handling crash site, bodies," Murphy tweeted.
The rebels have limited international observers' access to the crash, and reporters combing the area have found piles of intact objects that were moved.
Large fragments of the plane were found in areas that are unsecured, and some bodies have been "lying in the humid weather" for three days, according to on-the-ground tweets from Paul Sonne, a Moscow correspondent for the Wall Street Journal.
Micheline Maynard, a former senior correspondent for the New York Times, said it was clear the site is not being managed in the standard way.
"All the plane crashes I've covered were immediately secured, evidence carefully categorized. #MH17 sounds like chaos," she tweeted Saturday.