The suspects are carrying backpacks and can be seen walking on the sidewalk along the route of the Boston marathon towards the finish line. One of the suspects is wearing a dark cap, jacket and light trousers and is carrying a black backpack.
The other suspect is wearing a white cap and in one of the videos available with the FBI is seen planting his backpack at the site of the second explosion.
The FBI said the bag was planted at the marathon "within minutes" of before the blast. The pictures and videos were released during a press conference organsied here. FBI's Special Agent in-charge Richard DesLauriers said the two men "appear to be associated."
"At this time these are the people of interest to the FBI," DesLauriers said at the press conference. He cautioned that the public should not take any action against the two individuals and should contact law enforcement officials.
"Somebody out there knows these individuals... we consider them to be extremely dangerous," he said. The FBI has not made any comment on the nationalities of the two suspects. Two bombs ripped through the crowds and runners at the Boston Marathon, killing three persons and injuring over 180 on Monday.