A series of bomb threats in New York City and nationwide left many on edge Thursday.

Police say the threats were sent electronically to various locations in New York City, some with the subject line "think twice."

NYPD Counterterrorism says the threats are not considered credible and instead were meant to cause disruption.

Police say up to 40 threatening emails were circulated in New York City containing a bomb threat that was demanding bitcoin payment.

One threat went to the Bronx High School of Science at West 20th Street, which holds thousands of students.

A spokesperson for the Department of Education says the school was evacuated and temporarily relocated to designated school buildings before returning.

Another threat was sent to East Haven Nursing and Rehabilitation Center at 2323 Eastchester Road.

In Brooklyn, an employee at Tully Construction at 333 Avenue X says he called police after a threat was made.

Police say no devices were found following multiple searches.

The NYPD says they are continuing to investigate along with the FBI