Authorities in major cities across the United States said they were increasing police patrols in response to the attacks Friday in Paris, though police departments across the country said it did not appear that there was any threat to any of these places.

“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 in a statement.

Police in New York City were deployed “to crowded areas around the city out of an abundance of caution,” a department spokesman said in a statement.

“Tonight you’re going to see additional NYPD presence in some key locations around the city and certainly in front of the French government facilities here and the French Mission to the U.N. and the French Consulate,” Mayor Bill de Blasio said in an interview on NY1. “We learned through painful experience that we had to protect ourselves. … New York knows this all too well. And that’s why we know we have to be ready.”

Officers were sent to French government locations in New York immediately following the attacks, the police department said. The NYPD has been in touch with the Paris police as well as the FBI, city officials said.

“Tonight’s attacks in Paris are atrocities, and for the second time this year the Department sends its deepest sympathies to the citizens of the City of Light,” William J. Bratton, the New York police commissioner, wrote in a message to his department late Friday. “They have borne too much.”

Counterterrorism officers and other police would be deployed throughout the city because the NYPD “must rededicate ourselves to the mission of keeping this city and her people safe,” Bratton wrote in the message.

“It’s what we do,” Bratton said. “There is no known nexus between the attacks in Paris and New York City, but we are cops, and we are cautious.”

In Washington, officials said that Mayor Muriel Bowser had been briefed by Cathy Lanier, chief of the city’s Metropolitan Police Department.

“Out of an abundance of caution, the District has deployed additional law enforcement resources to French-owned sites and other high-profile locations,” District officials said in a statement. “There is no imminent threat to the District and MPD will continue to work with partners and monitor the situation closely.”

A fusion center for state and local law enforcement agencies in south Florida was monitoring the situation, the Miami-Dade Police Department said, adding that the Miami officers also remained on alert.

The Los Angeles Police Department said it was sending out extra patrols to “critical sites” and monitoring the ongoing situation, even though it said there were no known threats.

Police in Chicago also said there was also no immediate threat to that city and said they were “in constant contact with our federal and international partners to evaluate and respond to any changes in intelligence.”

Similarly, Boston police said they were also monitoring the situation and had increased law enforcement resources through the city.

“As of now there is no credible threat to Boston; however, we are encouraging officers to remain vigilant as they conduct their patrols,” the Boston Police Department said in a statement. “Additional law enforcement resources have been deployed throughout the city.”

This post has been updated. First published: 10 p.m.