A rash of bomb threats were reported Thursday against businesses, schools, hospitals and other places across the country, all of which so far appear to be hoaxes.

Police in cities nationwide reported the threats, some of which were emailed, while others were phoned in. In Wausau, a bomb threat was emailed to WSAW NewsChannel 7, according to a post on the news outlet’s website. Police cleared the building; no bomb was discovered.

Authorities in Oklahoma City, New York City, Massachusetts and Florida all confirmed bomb threats were sent to specific addresses within their states.

In New York City, police monitored “multiple bomb threats that have been sent electronically to various locations throughout the city,” the New York Police Department’s counter-terrorism bureau said on Twitter.

“These threats are also being reported to other locations nationwide & are NOT considered credible at this time,” the NYPD said.

New York police later said on Twitter that there was an “email being circulated containing a bomb threat asking for bitcoin payment” but that no devices had been found.

Police say the threats were “meant to cause disruption and/or obtain money.”

In Massachusetts, state police said on Twitter that it bomb squad unit was responding to “multiple bomb threats emailed to numerous businesses in the state.” Separately, Boston police said in a statement they had confirmed an emailed bomb threat to the Boston Opera House.

And in Colorado, a false bomb threat was made against Columbine High School, causing the school and 22 others nearby to be placed on lockdown, according NBC affiliate KUSA. On Thursday morning, a caller claimed to have “multiple explosive devices” inside the school, Mike Taplin with the Jefferson County Sheriff’s Department said, according to NBC affiliate WSAV.

In San Franciso, employees at a Jewish Community Center and multiple branches of the Fire Credit Union were evacuated after reports of emailed bomb threats, NBC Bay Area reported, and more than two dozen threats were being investigated in southern California.

The FBI in a statement said the organization is “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.”