A powerful blast from an explosive device injured at least 29 people in New York City's popular Chelsea neighborhood on Saturday night.
The explosion came just after 8:30 p.m. ET at 133 W. 23rd St., between Sixth and Seventh Avenue in a neighborhood known for its vibrant nightlife. City officials said police located the explosive device in the street next to a trash bin. The explosion was so powerful it blew out the windows in a nearby building. The city's fire department said none of the victims had life-threatening injuries, but witnesses reported seeing victims cut by shrapnel, metal fragments and glass. All those injured were released from area hospitals by Sunday morning, according to New York Gov. Andrew Cuomo's office.
WATCH VIDEO: Witness assists the injured at scene of a powerful explosion from a explosive device the injured at least 29 people in New York's popular Chelsea neighborhood on Saturday. Video courtesy of Ramón Lopez. Ramón Lopez / NorthJersey.com
A second device believed to be a pressure cooker was found on West 27th Street, four blocks from the initial blast on West 23rd. The New York Police Department said it was safely removed by the bomb squad early Sunday.
What caused it?
The explosion was from an apparent homemade device placed in front of a residence for the blind and near a major thoroughfare with many restaurants.
New York Mayor Bill de Blasio called it a bombing, but said the motivation remains unknown.
A law enforcement official told the Associated Press that the explosion appeared to have come from a construction toolbox in front of a building. Photos from the scene show a twisted and crumpled black metal box.
A second device believed to be a pressure cooker attached wiring and a cellphone and had been placed inside a plastic bag, the AP reported.
Was it a terror attack?
New York Gov. Andrew Cuomo said Sunday that investigators so far have not found any connection to international terrorist groups, and there is no further immediate threat to the city.
De Blasio called the incident an "intentional" act, but said the city had received "no specific and credible threat" from any terror organization.
WATCH VIDEO: Surveillance videos captured the explosion in the Chelsea neighborhood of New York City from multiple angles. USA TODAY
De Blasio also said investigators have so far found no connection to an incident earlier Saturday in Seaside Heights, N.J., in which a pipe bomb exploded near a Marine charity run. In that instance the device was placed in a garbage can. No injuries were reported.
How have police responded?
New York Police Department Commissioner James O'Neill said no individual or group has claimed responsibility, but officials said in a press conference Sunday that the investigation is ongoing.
De Blasio said police presence will be "bigger than ever." One thousand extra state police officers and National Guard troops have been dispatched to patrol subways, bus terminals and airports. K9 units and heavy weapons teams will also be employed throughout the city.
The blast comes as the United Nations General Assembly is meeting in New York, which has also caused increased police presence in the city.
Police are also continuing to collect evidence in the affected area, and a bomb squad is working on the device found on 27th street.
O'Neill said he reviewed one surveillance video footage, and investigators are reviewing more footage recovered from the scene and talking to witnesses.
WATCH VIDEO: 5 things to know about NYC explosion (USA Today)