New York Gov. Says Chelsea Blast Shows No Links To International Terrorism

A day after an explosion in Manhattan injured 29 people, New York authorities said all injured people have all been released from hospitals. They say they do not have evidence the blast is linked to international terrorism.

The damage to the site at West 23rd Street in New York City's Chelsea neighborhood is extensive, Cuomo told reporters on Saturday morning. "The force of the explosion, you can see it down the block, across the street. There's glass everywhere. Shrapnel everywhere." He added: "When you see the damage, I think we were fortunate that there were no fatalities." The explosion happened at around 8:30 pm Eastern time, as we reported.

At a press conference, New York Mayor Bill de Blasio summed up the current situation: "Here's what we know: It was intentional. It was a violent act. It was certainly a criminal act. It was a bombing. That's what we know."

But De Blasio emphasized that the motive for the attack remains unknown. "To understand if there were any specific motivations, political motivations, any connection to an organization – that's what we don't know," he said. "It could have been something personally motivated, we don't know yet." He added that "all possible theories of what happened here and how it connects will be looked at" during the investigation.

Cuomo said that there is "no reason to believe at this time that there is any further, immediate threat." But at the same time, nearly 1,000 New York State police and members of the National Guard will be deployed to bus terminals, airports and subway stations. Likewise, the NYPD's Chief of Department Carlos Gomez told reporters that they plan to beef up police presence in all five boroughs.

Authorities said the buildings surrounding the blast are structurally stable, and a nearby train station sustained no damage.

At this preliminary stage, Cuomo said, there are no clear links to international terrorist groups but they plan to eventually prosecute this as a terror crime:

"No one has taken credit, there have been no international groups that have put out any statements connecting them with this action. Now it depends on your definition of terrorism. But a bomb exploding in New York is obviously an act of terrorism, but it's not linked to international terrorism – in other words we find no ISIS connection, etc."

He added that a second device, found nearby on West 27^th St. and cleared by authorities, was "similar in design" to the first. Authorities are still working to determine whether the two devices are linked.

Petra Mayer, an editor for NPR books, was walking on West 27^th St. on Saturday night and stumbled upon the device: "I just happened to look down and I spotted a pressure cooker sitting on the sidewalk and it was covered in duct tape. I couldn't tell exactly what it was, but [it had] some kind of black, plastic rectangular device connected by two wires to this pressure cooker."

Another NPR staffer with Mayer called 911 and was later questioned by detectives about the device.

The suspicious item "looks a lot like the homemade bomb that was used during the Boston Marathon attack," as NPR's Dina Temple-Raston reported on Weekend Edition Sunday. "It isn't very complicated, and instructions for this kind of device have been on the internet for years.

FBI Assistant Director Will Sweeney told reporters that authorities are taking evidence collected to its facilities in Quantico, Va. for review.

Authorities are also investigating whether the two devices in New York are linked to a pipe bomb blast in Seaside Park, New Jersey on Saturday that happened before a charity race. Nobody was injured by that explosion. De Blasio said that at this point, authorities do not have any specific evidence of a link between the incidents.

This comes as New York is tightening security ahead of the U.N. General Assembly this week, where world leaders are set to convene in the city.