At least 10 New York City subway riders were shot Tuesday by a man wearing a gas mask and a green construction vest who tossed a smoke canister in the train car to distract the rush hour crowd before opening fire, officials and law enforcement sources said.
Five of the gunshot victims were said to be critically injured. Details on the nature of their wounds weren't immediately clear. No fatalities have been reported.
The smoke canister, and harrowing video from the train, prompted early concerns about possible explosive devices connected to the case, but New York Police Department Commissioner Keechant Sewell assured New Yorkers in an early afternoon news conference that there are no known explosive devices on any subway trains in the city at this time.
Get Boston local news, weather forecasts, lifestyle and entertainment stories to your inbox. Sign up for NBC Boston’s newsletters.
The shooter remained on the loose more than three hours after he opened fire on the train at the 36th Street and Fourth Avenue station in Brooklyn around 8:30 a.m.
The Massachusetts Bay Transportation Authority said in a statement that it is closely monitoring the situation in New York, and Transit Police are engaged with federal, state and local law enforcement officials to share and obtain any available intelligence.
"At this time, there is no evidence, credible or otherwise, to suggest the MBTA system is a potential target," the MBTA said.
"The Transit Police employ a multi layered approach to safeguarding the MBTA system. To reassure our riders, the Transit Police Department has increased the number of uniformed officers on the system and deployed additional Explosive Detection K9 teams to perform protective sweeps. There are also actions police will employ that will not be visible to the riding public."
"The safety and security of customers and employees is the MBTA's top priority. If riders using the T see anything out of the ordinary, they are urged to contact Transit Police or MBTA personnel immediately."
MBTA Transit Police Chief Kenneth Greene said his department was taking extra steps like increasing patrols of regular officers as well as explosive detection teams, which will sweep for anything suspicious.
Massachusetts State Police said they are monitoring intelligence related to the shooting in coordination with federal and local law enforcement partners. There is no known threat or nexus to Massachusetts, state police said on Twitter.
Boston police said they are monitoring the situation in New York City and are in contact with police there. They said they will also be increasing their presence around subway stations in Boston, though they said there is no threat to the city at this time.
The FBI Boston Division said it is also monitoring the events in New York City and coordinating with other law enforcement agencies.
"At this point in time, FBI Boston has no specific, credible information that would suggest a pending threat to our area of responsibility," the agency said.
“I do want to start just by saying that our thoughts and prayers and every bit of well wishes are with the city of New York with the experience that they’ve had on the MTA earlier today," Boston Mayor Michelle Wu said at a press conference Tuesday. Wu said she did speak briefly with New York City Mayor Eric Adams and that local public safety officials were coordinating with their partners in New York.
"We are following very closely and wishing them every bit of strength right now," Wu said.
Massachusetts Gov. Charlie Baker was also asked about the subway shooting, especially given that the Red Sox home opener and Marathon Monday are coming up in the next week. But he said there should be no cause for alarm here.
"The state police, federal government and local law enforcement and transit police have been talking all morning and there will be a much more significant presence throughout the rest of the day," he said. "But we have not been made aware of anything that involves Massachusetts specifically. I don't think people need to be concerned about that. But they will see a really significantly stepped up presence."