The Federal Bureau of Investigation is searching for more information on two unknown individuals who were spotted on camera taking a homemade bomb out of a piece of luggage before leaving it behind.

The men appear to have some possible involvement with explosives left in the Chelsea neighborhood in New York. The main suspect in that case – in which a homemade bomb injured 31 people – was arrested early Monday morning. Ahmed Khan Rahami of Elizabeth, New Jersey, was arrested in Perth Amboy after a shootout with police. His fingerprints were also found on explosives left at the Elizabeth train station and in a garbage can on a charity 5K race path in Seaside Park, NJ.

Police did not give any indication as to who the individuals in the photo are or what their role is in connection with leaving bombs around the city, but the F.B.I. has released their photo.

According to the F.B.I., the pair saw a piece of luggage on the sidewalk, removed an improvised explosive device from the luggage, and then left leaving the device behind but taking the luggage.

The image was taken within the same hour that an explosive device detonated on West 23rd Street.

Law enforcement had previously told reporters that surveillance footage had identified two men handling the luggage. “Two men captured on video surveillance Saturday night can be seen opening the bag on West 27th Street, removing the bomb from the suitcase, placing it on the sidewalk and then walking away with the suitcase,” the New York Post reported, quoting NYPD Chief of Detectives Robert Boyce describing the men as “incredulous” when they opened the suitcase. Police have not confirmed whether these two men are the same men who law enforcement officials are now seeking for further investigation.

Law enforcement officials have repeatedly noted there is “no indication” that Rahami did not act alone, though evidence in the court indictment against Rahami suggests that he used mobile phones tied to unnamed relatives to record the detonation of a test explosive and as remote controls to detonate the weapons in Seaside Park and Chelsea.