Senator Bernie Sanders‘ Burlington office was evacuated Thursday after police deemed a package delivered there to be suspicious, authorities said. Burlington police said in a press conference that the suspicious package was not an explosive device and was deemed “harmless.”

Sanders was in New York City on Thursday for a taping of “The Late Show with Stephen Colbert.” His 2020 campaign stated they do not comment on matters of security.

Police said it was unclear what was in package and who sent it. The U.S. Post Office will be launching an investigation.

Investigators were called around 11:45 a.m., CBS Burlington affiliate WCAX-TV reports. The building was evacuated around 4 p.m., the station said.

Burlington police tweeted state police had responded as well.

Cara Korte contributed reporting.

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