NATIONWIDE — Law enforcement agencies and first responders scrambled to hundreds of bomb threats emailed to businesses and buildings around the nation Thursday.

The threats began to come into fire departments and agencies at about noon. They were reported from west to east coast and forced temporary evacuations of buildings, institutions, and offices, and lockdowns at nearby schools. Some buildings closed early after the threat.

It's unclear whether all of the threats were connected.

There were no immediate reports of injuries.

"We've received updated information that this is a nation-wide hoax threat," said a spokesman for Seminole County (Florida) Public Schools, where a high school and elementary school were temporarily placed on partial lockdowns.

The threats were sent to a wide variety of institutions and organizations, including newspapers, medical facilities, schools, universities, law firms, and banks. The New York City Police Department said the threats of which they were aware contained a ransom for Bitcoin payment.

Some of the emails had the subject line, "Think Twice," the Associated Press reported.

According to a Facebook post by the Cedar Rapids (Iowa) Police Department, at least some of the emails contained the subject line, "Do not waste your time," and said a "Hexogen" explosive device had been hidden in the email recipient's building. 

The email, which contains misspellings and grammatical errors, says, in part:

"I can call off my man if you make a transfer. 20.000 dollars is the cost for your life and business. Pay it to me in BTC and I warrant that I will withdraw my man and the device won't detonate. But do not try to cheat- my guarantee will become valid only after 3 confirmations in blockchain network. ... Nothing personal this is just a business, if you don’t transfer me the bitcoins and a bomb explodes, next time other companies will send me more money, because this is not a one-time action."

The NYPD Counterterrorism Bureau said on Twitter that they were monitoring multiple bomb threats that were sent electronically to locations across the city, though they were not being considered credible at as of Thursday afternoon.

The Charlotte-Mecklenburg Police Department in North Carolina tweeted that their department was also responding to multiple reports of the unsubstantiated bomb threats. The News & Observer newspaper in Raleigh reportedly received the threat. And in Boone, North Carolina, the fire department, police department and Sheriff's Office all responded to a similar threat on State Farm Road.

Orlando's police and fire departments said they were assisting federal law enforcement in the investigation. Orlando firefighters said they had responded to least a half-dozen bomb threat reports.

Email threats were also sent to at least one city in Canada, according to CNN. Vancouver Police confirmed to the news network that several businesses there received them.

"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," FBI Tampa Division spokeswoman Andrea Aprea said in a statement. "As always, we encourage the public to remain vigilant and to promptly report suspicious activities which could represent a threat to public safety."

Map: Locations where threats were received

Agencies, institutions report receiving threats