A North Carolina Republican headquarters was firebombed and vandalised overnight, local officials revealed on Sunday (16 October). The attack was condemned by local officials and both presidential candidates, with GOP nominee Donald Trump placing the blame on "animals that represent Hillary Clinton".

"The flammable substance appears to have ignited inside the building, burned some furniture and damaged the building's interior before going out. The substance was housed in a bottle thrown through one of the building's front windows," the town of Hillsborough said in a statement.

A swastika and the words "Nazi Republicans get out of town or else" were spray painted on a neighbouring building, CNN reported. No one was hurt in the attack and damage estimates are still not available.

The incident is being investigated by the Hillsborough police and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, the Charlotte Observer reported.

North Carolina Governor Pat McCrory called the firebombing "an attack on our democracy". McCrory added, "Violence has no place in our society—but especially in our elections....I will use every resource as governor to assist local authorities in this investigation."

Meanwhile, GOP nominee Donald Trump took to Twitter to place the blame firmly with his rival and the Democratic Party. "Animals representing Hillary Clinton and Dems in North Carolina just firebombed our office in Orange County because we are winning @NCGOP," Trump tweeted.

Clinton did not address the accusations, but did speak out against the attack. "The attack on the Orange County HQ @NCGOP office is horrific and unacceptable. Very grateful that everyone is safe," she wrote. The North Carolina Republican Party wrote back: "Thank you for your thoughts & prayers, Sec. @HillaryClinton."

Dallas Woodhouse, the executive director of the North Carolina Republican Party, also condemned the "hate-filled" attack. "Whether you are Republican, Democrat, or Independent, all Americans should be outraged by this hate-filled and violent attack against our democracy," he said in a statement, according to Politico.

The party also responded to Trump's second tweet: "Thank you Mr. @realDonaldTrump. We will not be silenced nor suppressed by this evil act. We will pray for those who seek to harm us."

North Carolina is among the highly contested battleground states in the 2016 elections. Orange County, where the incident took place, is overwhelmingly Democratic. According to the Charlotte Observer, Democrats and independents outnumber Republicans five to one.