The Republican campaign headquarters was firebombed in Hillsborough, North Carolina, on Saturday night, police said.
A flammable liquid was tossed through the front window of the office, setting the interior on fire temporarily and damaging furniture, the Hillsborough Police Department said in a statement.
"The flammable substance appears to have ignited inside the building, burned some furniture, and damaged the building’s interior before going out," police said. "The substance was housed in a bottle thrown through one of the building’s front windows."
Vandals also spray-painted a building next door with a swastika and the words "Nazi Republicans get out of town or else."
No one was in the building at the time, and police are investigating the act as vandalism and "hate graffiti."
Hillary Clinton issued a statement on Twitter Sunday calling the attack "horrific and unacceptable."
Hillsborough Mayor Tom Stevens also issued a statement about the vandalism.
“This highly disturbing act goes far beyond vandalizing property; it willfully threatens our community’s safety via fire, and its hateful message undermines decency, respect, and integrity in civic participation," Stevens wrote Sunday.
“Acts like this have no place in our community. Our law enforcement officials are responding quickly and thoroughly to investigate this reprehensible act and prosecute the perpetrators.”
North Carolina Governor Pat McCrory called the incident "an attack on our democracy."
"Violence has no place in our society — but especially in our elections," McCrory said in a written statement. "Fortunately no one was injured; however, I will use every resource as governor to assist local authorities in this investigation.”
The Hillsborough police did not immediately return BuzzFeed News' request for more information.
North Carolina GOP spokesperson Kami Mueller tweeted pictures of the incident, saying the act "will not deter good people from exercising their rights."
By Sunday night, Democrats had rallied to raise more than $13,000 toward reopening the GOP office.
"This is not how Americans resolve their differences," a GoFundMe page said. "We talk, we argue, sometimes we march, and most of all we vote. We do not resort to violence by individuals or by mobs.
So, let's all pitch in, no matter what your party affiliation, in and get that office open again quickly."
Within 40 minutes, the GoFundMe surpassed its $10,000 goal — a victory for democracy and civility, campaign organizer David Weinberger wrote on Twitter.