Multiple institutions across the United States received emails and phone calls threatening bomb attacks Thursday, which caused evacuations and law enforcement actions but were mostly confirmed by police as "not credible."
The Federal Bureau of Investigation (FBI) said in a statement that it was aware of the recent bomb threats made in cities around the country. "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," the FBI said.
Law enforcement agencies across the country dismissed the threats, saying they were meant to cause disruption and compel recipients into sending money, and were not considered credible.
The New York Police Department (NYPD) tweeted that it was monitoring "multiple bomb threats," and "these threats are also being reported to other locations nationwide & are NOT considered credible at this time."
CNN reported that it was not yet clear whether these threats were connected. The threats, it said, had been received in San Francisco, New York, Seattle, Miami, Washington D.C. and other locations nationwide, targeting universities, hospitals, courthouses as well as media groups.
The news cable also reported that an email demanding 20,000 U.S. dollars via Bitcoin was forwarded to its affiliate KOCO-TV in Oklahoma City by a viewer who received it at her business. "It's unclear whether everyone who received a threat on Thursday received the same email," CNN said.
Emailed bomb threats demanding Bitcoin payments were also sent to locations in New York City, according to the NYPD.
Searches had been conducted at those locations and no devices had been found, NYPD Sergeant Jessica McRorie told Xinhua. "At this time, it appears that these threats are meant to cause disruption and/or obtain money," she added.
Credibility of these threats "can be assessed in context as likely not credible," said the sergeant, adding that they would respond to each call regarding these emails to conduct a search.
The University of Washington in Seattle issued a campus-wide alert saying the FBI had "advised that the email is not a credible threat," and concluded sweeps of possibly affected buildings.
The Pennsylvania State University said in a statement that its police were coordinating with the FBI in "investigating a message received by individuals in multiple locations on campus and across the state," adding that the threat "does not appear to be a legitimate threat, however, an investigation is ongoing."
The police later concluded that the threat "appears to be a hoax."
"We have received information that several other cities across the United States have received similar threats," police department said in San Francisco, California.
Also in California, the Los Angeles Police Department (LAPD) said that several of those threats have been received in the Los Angeles area.
"We are working diligently to determine the source & credibility of these threats. We will provide more information as it becomes available," the LAPD said via its official Twitter account.
In Massachusetts, police tweeted that its bomb squad unit was responding to "multiple bomb threats emailed to numerous businesses in the state."
"NO indications of any explosives located or detonated to this point. We will continue to communicate info when available," Massachusetts State police tweeted later.
Local businesses in Florida, a courthouse in Utah, two news organizations in North Carolina, and several streets in Chicago, Illinois were also targeted by the threats.
"Random email threats in Chicago are part of a similar pattern being made nationwide. We are working with federal partners on the investigation, and at this time there is no elevated threat level for the City of Chicago," tweeted Chicago Police Department. The city received 15 to 20 reports of emailed threats, according to the police.
Earlier in the day, a false bomb threat was made against Columbine High School in Colorado, causing the school and 23 other schools nearby to be placed on lockdown.
