On Thursday, a large number of schools, businesses, and hospitals in both the U.S. and Canada were targeted by bomb threats, causing evacuations across the two countries.
Cities that received threats include New York, Miami, Chicago as well as Canadian hubs Vancouver and Toronto, among others. It's unclear if all the threats are related.
The threats were sent via email. As of Thursday evening, officials in many of the cities said they don't believe anyone who received a threat was in legitimate danger.
In a tweet, the FBI said that they were aware of the threats and are working on assisting law enforcement.
Additional reporting from Newsy affiliate CNN.