The incidents around the country are all similar in nature, with the perpetrator or perpetrators demanding money be put into Bitcoin.
Houston police confirmed that they are investigating at least five such threats.
Other agencies are investigating as well.
Like other law enforcement agencies across the country, we have received several reported bomb threats. None of the Houston calls were valid. We remind everyone to remain vigilant and if you see something suspicious, please report it immediately. #hounews— Houston Police (@houstonpolice) December 13, 2018
RPD is investigating two bomb threats within the city. There have been similar threats called into several locations around the country. No credible threat found at this point. Please continue to be vigilant and report anything suspicious. pic.twitter.com/AAiSwefAu1— Rosenberg Police (@RosenbergPolice) December 13, 2018
We are aware of recent bomb threats received via email here in Harris County and across the nation. We're working with federal, state and local partners to identify the source. Residents are urged to be vigilant and promptly report suspicious, threatening activity. #hounews pic.twitter.com/jLFkUxU1dc— HCSOTexas (@HCSOTexas) December 13, 2018
We are currently monitoring multiple bomb threats that have been sent electronically to various locations throughout the city.— NYPDCounterterrorism (@NYPDCT) December 13, 2018
These threats are also being reported to other locations nationwide & are NOT considered credible at this time. pic.twitter.com/GowGG4oZ9l
Up to a dozen emails were sent to businesses and schools in Washington, D.C.
Across the country, some schools were closed early and others were evacuated because of the threats. Penn State University notified students via a campus alert. Near Atlanta, people were ushered out of a courthouse.
The FBI also issued a statement:
"We are aware of the recent bomb threats made in cities around the country, and we remain in touch with our law enforcement partners to provide assistance. As always, we encourage the public to remain vigilant and to promptly report suspicious activities which could represent a threat to public safety."