A local Republican Party office in North Carolina has been damaged by fire and someone spray-painted an anti-GOP slogan referring to “Nazi Republicans” on a nearby wall, authorities said Sunday.

A news release from the town of Hillsborough said someone threw a bottle filled with flammable liquid through the window of the Orange County Republican Party headquarters overnight. The substance ignited and damaged furniture and the interior before burning out.

The news release says an adjacent building was spray-painted with the words: “Nazi Republicans leave town or else.”

RELATED: GOP office reopens after firebombing in North Carolina

State GOP director Dallas Woodhouse says no one was injured, but a security alert is being sent to party offices around the state.

Democratic presidential nominee Hillary Clinton offered her sympathies on Twitter, calling the attack “horrific and unacceptable” and saying she was “grateful that everyone is safe.”

Her GOP rival, Donald Trump, initially linked the attack to the Democrats, tweeting: “Animals representing Hillary Clinton and Dems in North Carolina just firebombed our office in Orange County because we are winning” before following up a more sympathetic: “ALL SAFE IN ORANGE COUNTY, NORTH CAROLINA. With you all the way, will never forget. Now we have to win. Proud of you all!”