Nassau and New York City police were intensifying patrols following an explosion at an Ariana Grande concert in England Monday night, but said no local imminent threats were known.

Nassau police said it will beef up patrols at large public gatherings, while the NYPD said it will deploy its strategic response group, composed of officers trained in fast response.

Suffolk police said it will adjust deployment of officers if necessary and also said no credible threats have been identified.

The police departments said they were monitoring developments with various agencies, including the FBI.

Officials expressed their prayers and condolences to the victims of the Manchester explosion and their families.

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Nassau police asked the public to report anything suspicious to 911. Tips may also be left at Nassau County Crime Stoppers, 800-244-TIPS.

Gov. Andrew M. Cuomo called it an “inexplicable and abhorrent assault” and ordered a boost in security at certain locations. “Out of an abundance of caution, I have directed state law enforcement officials to step up security and patrols at high-profile locations across New York, including our airports, bridges, tunnels and mass transit systems,” he said in a statement.