New York, Boston and other cities in the United States bolstered security on Friday night after deadly gun and bomb attacks on civilians in Paris, but law enforcement officials said the beefed-up police presence was precautionary rather than a response to any specific threats.
The New York Police Department said officers from its Counterterrorism Response Command and other special units were deployed in areas frequented by tourists, and at the French Consulate in Manhattan.
"Teams have been dispatched to crowded areas around the city out of an abundance of caution to provide police presence and public reassurance as we follow the developing situation overseas," the NYPD said in a statement.
New York, the site of the Sept. 11, 2001 hijacked plane attacks that killed nearly 3,000 people and destroyed the World Trade Center's twin towers, is considered a top target for attacks by Islamist militants.
The nearly simultaneous gun and bomb attacks in Paris may have killed 140 people in various places across the French capital and wounded many others
The NYPD did not say how many extra officers were sent to guard the areas of concern nor did it specify the areas where the extra officers were sent.
"Every time we see an attack like this it is a reminder to be prepared, to be vigilant," New York Mayor Bill de Blasio told ABC 7 television.
New York Governor Andrew Cuomo said he directed state law enforcement officials to monitor the Paris "situation for any implications in New York state and remain in constant communication with their local and federal partners."
The Port Authority of New York and New Jersey said police were on heightened alert at all of the agency's bridges, tunnels and rail facilities, as well as at the World Trade Center in lower Manhattan. It said it was increasing patrols and checking of bags, buses and trains.
U.S. Department of Homeland Security Secretary Jeh Johnson said in a statement that "we know of no specific or credible threats of an attack on the U.S. homeland of the type that occurred in Paris tonight."
The National Basketball Association, which had 11 games on the schedule Friday night, said it was increasing security at each of the venues. The most popular sport, American football, would not have any games until Sunday as previously scheduled.
"Security at our games is always at a heightened state of alert," National Football League spokesman Brian McCarthy said.
Outside of New York, law enforcement and transportation agencies said they were also on high alert.
The U.S. Capitol Police in Washington boosted patrols around the Capitol complex, a spokeswoman said. "There is currently no known threat to the Capitol Complex," she said in an email.
In Boston, the police department said it deployed additional resources and was working closely with federal authorities, but saw no credible threat in the city, where Islamist militant sympathizers set off home-made bombs at the Boston Marathon finish line in April 2013. Massachusetts State Police said they took "several actions," including bolstering security around the State House in Boston.
"We are encouraging officers to remain vigilant as they conduct their patrols, the Boston Police Department said in a statement.
The St. Louis Police Department said it added an extra layer of security for the World Cup soccer qualifying match between the United States and St. Vincent Friday night.
Chicago police said they were following developments in France to determine whether to bolster city security but that there were no immediate threats.
"Tonight the City of Chicago stands shoulder to shoulder with the City of Paris in the wake of today's despicable and horrifying attacks," Mayor Rahm Emanuel said.
Amtrak, the U.S. passenger train service, said it was monitoring the events in Paris but said there were no specific or credible threats against the railway.