Following Friday's terror attacks in Paris, cities around the world have moved to bolster their security. In most cases, the measures have been largely precautionary. However, Washington, D.C., and New York added the safeguards after being identified by the Islamic State militant group as targets, though there are no clear, verified threats against either city.
"At this time, we know of no specific or credible threats of an attack on the U.S. homeland of the type that occurred in Paris tonight," Homeland Security Secretary Jeh Johnson said shortly after the attacks.
Here's a brief rundown of how major cities in the U.S. have reacted to the attacks.
The Islamic State, also known as ISIS, publicly named Washington, D.C., as a target several days after the attacks in Paris. While D.C. police say they haven't picked up on any specific, credible threats to the city, officials nonetheless responded by increasing security.
"You can't take anything for granted. When you have people that are pushing that type of agenda, the fact that there are people out here who might take that action based on seeing that video, we have to take all of that seriously," Metropolitan Police Department Chief Cathy Lanier told NBC Washington.
She encouraged residents to go about their business as they normally would.
The Capitol Police Board, which is responsible for security at the U.S. Capitol and the surrounding buildings, acknowledged in a statement this week that the Capitol will "always be an appealing target.” Though there are no specific threats, the department said it has "increased presence and visibility" as "a proactive enhancement of our already heightened security posture."
The Metro Transit Police Department has increased patrols and K9 security sweeps, and will be conducting more explosives screenings. The department also said it has "implemented several other countermeasures that are not visible to the traveling public" in tandem with local and federal agencies.
A video released by the Islamic State on Wednesday appeared to specifically call out New York City as a target, but authorities said the video wasn’t accompanied by any clear, credible threat.
“Footage of New York shown in the ISIS video was taken from a video released by the group in April of this year,” Rita Katz, director of the SITE Intelligence Group, told Reuters. “So while NYC is, and has been, a target for ISIS, today’s video does not warrant any kind of panic.”
Before that, the New York City Police Department had already deployed a rotating force of 500 counterterrorism officers in the city, at least 100 of whom will be on duty at any given time throughout the day. Eight K9 officers will also join in the effort.
Police Commissioner William Bratton said in an interview with MSNBC's "Morning Joe" on Monday that the department will send a team to Paris this week "to learn as much as we can about what was new about this attack," and indicated that the force will develop new procedures specifically for responding to terrorists with suicide vests.
Bratton acknowledged the possibility that New York City could experience an attack like the one that happened in Paris. But he said that since 9/11, the city "has constantly been preparing for and trying to protect against" similar attacks, and has successfully thwarted 20 would-be plots.
"So far," Bratton added, "we've been successful."
By chance, Chicago is hosting the 21st annual Joint Counterterrorism Awareness Workshop this week. The event has drawn more than 200 experts, who will run through potential terrorist scenarios and discuss how best to prevent them and how to respond in the event of an attack.
“The vile and vicious attacks of the terrorists are a reminder that our freedoms are fragile,” Chicago Mayor Rahm Emanuel told the crowd at the opening of the conference. “I think this is an essential effort to reassure the public we’re on task, doing the work that’s necessary."
However, he added that "there is no viable threat over the city of Chicago."
Viable threat or not, Chicago has nonetheless increased security across the metro area, stationing extra officers and K9's at sporting events and public transit hubs, according to NBC Chicago.
The Los Angeles Police Department will join New York in sending a team to Paris to learn more about the attacks and how to respond in the event of a similar tragedy.
Law enforcement there has also stepped up its patrols of "critical sites," including the airport, power grids and other public infrastructure, and various tourist attractions, including the Hollywood sign.
LAPD spokesman Officer Drake Madison stressed to KTLA that the department's actions are purely precautionary. There's "no nexus to anything in Los Angeles at this time," he said.
A flight from LA to Paris was diverted to Salt Lake City Tuesday night after a bomb threat, but no credible threats were found.
“We have trained everybody to come together to immediately converge … to immediately respond to stop an incident as soon as humanly possible,” LAPD Chief Charlie Beck told NBC. “What happened in Paris could happen in one of our American cities … It is very hard to stop determined individuals who are willing to sacrifice their lives and have access to assault weapons from creating some form of chaos."
During a scheduled stop in Los Angeles on Monday, Vice President Joe Biden spoke briefly on the attacks in Paris and sought to temper fears of an attack.
"I say to the American people: There is no existential threat to the United States,” Biden said. “Nothing ISIS can do could bring down the government, could threaten the way we live."
"ISIS will not prevail. It offers nothing but destruction. It offers nothing but twisted ideology that is not sustainable,” Biden continued. “Terror is designed to inspire terror. And we lose, they win, the moment we give in to that terror."
The San Francisco Police Department "went on heightened alert" following the Paris attacks, San Francisco Police Chief Greg Suhr told NBC Bay Area. Suhr said the SFPD has increased the number of officers on patrol, with an emphasis on entertainment districts and other places where crowds are likely to gather.
There are no known, specific threats in the Bay Area at this time, per a statement from SFPD.
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