New York: A bomb that injured 29 people on Saturday in the Chelsea neighbourhood of Manhattan, and another that failed to detonate, were filled with shrapnel and made with pressure cookers, flip phones and Christmas lights to set off a powerful explosive compound, law enforcement officials said on Sunday.
Both bombs appeared designed to create maximum chaos and fatalities. They also provided a trove of clues even as any suspects remained unnervingly at large.
A top law enforcement official said pressure cookers were filled with “fragmentation materials.”
The bomb that exploded, at 23rd Street, was filled with small bearings or metal BBs. A second device on 27th Street that did not explode appeared to be filled with the same material, the official said.
Late Sunday night, a law enforcement official said investigators stopped a car on the Belt Parkway near the Verrazano-Narrows Bridge and took five people to an FBI office in Manhattan for questioning in the bombing investigation. The official said all or most of them may have been from the same family and they may have been on their way to the airport.
The FBI confirmed in a statement that agents and police detectives had stopped “a vehicle of interest in the investigation into Saturday’s bombing in Manhattan and that no one has been charged with any crime.”
Earlier, two senior law enforcement officials said there was a “person of interest” in the bombing, but it was unclear if that person had been identified. The person had been seen on surveillance footage.
Tensions in the region, already high, escalated later Sunday night when what the authorities suspected could be a bomb was found near a train station in Elizabeth, New Jersey. The mayor, J. Christian Bollwage confirmed that a suspicious package containing “wires and a pipe” had been found by two men in the city, and said that the FBI and the New Jersey State Police had been called in to investigate after a drone tested the item and found that it could be a bomb.
A top law enforcement official said that pressure cookers in the two bombs in Chelsea on Saturday night were filled with “fragmentation materials.” The bomb that exploded, at 23rd Street, was filled with small bearings or metal BBs. A second device on 27th Street that did not explode appeared to be filled with the same material, the official said.
Senior law enforcement officials also said they were increasingly focused on the possibility that the attack was connected to a bombing Saturday morning in New Jersey, but the authorities still needed to compare all the bombs before drawing any conclusions. There, three pipe bombs were tied together, placed in a trash can and also employed by a flip phone as a timing mechanism, according to officials.
Officials said they did not know of any motive — political or social — for any of the attacks. Early Sunday, Gov. Andrew M. Cuomo said “there is no evidence of an international terrorism connection with this incident,” noting that no international terrorist group had claimed responsibility.
The search for the person or people behind the Chelsea attack took on added urgency as President Barack Obama and leaders from around the world were set to travel to New York for the annual UN General Assembly this week.
Tests showed that the explosive material in the 23rd Street bomb was similar to a commercially available compound called Tannerite, according to two law enforcement officials. It was unclear why Cuomo and Mayor Bill de Blasio dismissed with such certainty a tie to international terror. Experts said the bomb’s construction offered conflicting clues.
Tannerite is made by combining ammonium nitrate and aluminium powder, is frequently used in exploding targets at firearms ranges and has rarely been used in improvised explosive devices in the United States. But the materials are easy to buy in this country because each one on its own is not an explosive.
At the same time, pressure cookers have been a container of choice for many improvised explosive devices over the years. They were used in the deadly Boston Marathon bombings in 2013 based on a model in publications put out by al-Qaida’s affiliate in Yemen.
An expert on IEDs used by terrorists around the world said that a device constructed with a cell phone as a timer and Christmas lights as an initiator would indicate a higher-than-average competence than is usually found in the United States. “Most of what we see in the United States is a pipe bomb with black powder or smokeless powder or a simple hobby fuse,” said the expert, who spoke on the condition of anonymity because he does sensitive work for government agencies. “This would be the high-end of sophistication for IEDs in the United States.”
The recovery of the second device provides investigators with a host of potential leads, from the phone and other materials inside the homemade bomb to the pressure cooker itself — including possibly determining when and where it was purchased — to any possible fingerprints on the device, its components or the tape that held it together.
Cuomo said he was ordering an additional 1,000 New York State Police officers and National Guard members to be dispatched to major commuter hubs, and de Blasio said New Yorkers should expect to see a heightened police presence throughout the city, including additional patrols by the city’s heavily armed counter terrorism units.
The police continued to search the area around the blast site and fanned out across the city chasing leads and trying to sort through a variety of claims of responsibility — from Twitter to websites to 911 calls — most of which were dismissed as unrelated.
Late Sunday, FBI agents were seen dismantling the car of an Uber driver, who said the law enforcement officials were searching for possible evidence related to the attack.