TULSA, Oklahoma - The Tulsa Police Department said they have received notices of bomb threats sent by email as have other law enforcement agencies across the country.  

TPD said bomb threats have been sent to six different businesses - including several medical offices. The email demands that money be sent to an account or buildings will be blown up. The scammers are demanding $20,000 in Bitcoins, according to police.

Many of the places evacuated immediately and said they didn't know what to do.

Police said they sent officers to check out the businesses that received the threats but found no evidence supporting the bomb threats.

If you get a bomb threat, they ask you to save the email and contact them right away.

The Tulsa Bomb Squad said it's a new twist on the phone calls demanding people put money on gift cards or they or a loved one will be going to jail.

Oklahoma City police officers have responded to at least nine threats, and none have been credible. 

Police said bomb threats across the nation have been made Thursday through email. The email says a man walked into the building and placed a bomb there and if they didn't pay a sum in Bitcoin that the bomb would go off.

One of the businesses that received the threat in Tulsa was a pregnancy center. They are a non-profit and just don't understand why they were one of the ones that received the threat - but of course, they took it very seriously and evacuated immediately.

"We wanted to respond correctly and make sure everyone was safe, so that's why we started with the police department," said Karen Alley of Hope Pregnancy Center.

"They responded quickly, and we are very grateful to TPD for coming out and taking care of us and alleviating our fears."

Tulsa Police said it is now an FBI investigation, and they are doing everything they can to assist.

"Right now we haven't been able to associate any type of special pattern with the businesses here in Tulsa, but the FBI is looking into it on a national scale," said Sergeant Jacob Thompson, Tulsa Bomb Squad.