(RNN) - Authorities across North America responded to a wave of email bomb threats that flooded inboxes Thursday, threatening businesses, schools and newspapers.
The emails came with the subject line: “Think twice," or ”We can make a deal."
The public was told to remain calm and notify authorities immediately if they received a threat.
No devices have been found. No injuries have been reported.
The FBI said it was aware of the threats.
“We remain in contact with our law enforcement partners to provide assistance,” the FBI in Houston tweeted. “As always, we encourage the public to remain vigilant and to promptly report suspicious activities which could represent a threat to public safety.”
The threats came in the form of an email, demanding $20,000 in bitcoin, a digital currency.
“You must pay me by the end of the working day, if you are late with the transaction the bomb will explode,” the email read. “We arent (sic) terrorists and do not assume any responsibility for acts of terrorism in other places."
Television stations were affected as were newspapers such as The Chicago Tribune and the Raleigh News and Observer.
Police departments large and small reported the threats.
“At this time, it appears that these threats are meant to cause disruption and/or obtain money,” the New York Police Department said. “We’ll respond to each call regarding these emails to conduct a search but we wanted to share this information so the credibility of these threats can be assessed as likely NOT CREDIBLE.”
The Columbia, SC, Police Department also reported numerous threats.
“No hazardous materials found at this time. Officers are sweeping other locations,” the department tweeted. “Similar threats have been experienced across the U.S.”
Smaller communities, such as Price City, UT, were also handling multiple threats.
“At the time of this posting ... there have been approximately 50 of these in Utah, with at least one occurring (here),” Price City Police said. “There is no indication that these are credible threats at this time, but we also don’t want to take any chances.”
Price City is located about 100 miles southeast of Salt Lake City.
The threats also spread north of the border to Canada.
A subway station in Toronto was evacuated. Calgary Police said they were responding to multiple bomb threats.
“At this time we don’t have any reason to believe they are credible,” the department tweeted. “However, out of an abundance of caution we are treating each as if it is real. We are also aware of similar events occurring across the continent.”
Tom Scott said he received one of the emails. He posted it on Twitter.
“The Bitcoin-spam-scammers have moved on from fake blackmail threats to fake bomb threats,” Scott said. “So far no-one’s paid anything to the address, and I suspect it’ll stay that way.”
Earlier this year, an email scam involving bitcoin and so-called “sextortion” blackmail threats targeted individuals and businesses around the world.
The Electronic Frontier Foundation described those as phishing attacks in which “a hacker claims to have compromised your computer and says they will release embarrassing information” unless they were given bitcoin.
Bitcoin is a digital currency that functions through blockchain technology, in effect a decentralized coding technique that accounts for each block as a “coin.” As of Thursday they’re worth more than $3,000.