Bomb threats that were made at various voting centers across the United States appear to have come from Russian email domains, according to the FBI, officials told our partner network NBC News.

No threats resulted in the discovery of an explosive device and no one was injured.

There is also no indication that voting was disrupted, although in Pennsylvania, election officials asked the court to approve additional voting hours because voting had been temporarily suspended to investigate the allegations.

“The FBI is aware of bomb threats to polling locations in several states, many of which appear to originate from Russian email domains,” the FBI said in a statement this evening.

It’s also important to note that cybersecurity experts say it’s possible for threats to be sent from a certain country’s domain, but the person(s) sending the threats could be in another country.

The FBI is tracking and investigating bomb threats attributable to Russian domains in Georgia, Wisconsin, Michigan and Arizona, according to a senior FBI official.