BOSTON (KPEL) -- The FBI released video and photos of the suspects they believe are responsible for the twin bombings at Monday's Boston Marathon.

Below is video taken from a surveillance camera, depicting the two suspects.

At a 4:00 p.m. press conference, FBI Special Agent-in-Charge Richard DesLauriers called for the public's assistance in solving the case.

The FBI showed video of the two men walking through the crowd, each wearing a backpack, presumably with a bomb inside. They appear calm, and don’t attract any attention from anyone they pass by about 12 minutes before the first bomb blast.

Apparently there is also video of the man in the white cap, called “Suspect No. 2,” actually planting one of the bags that later exploded, but the FBI did not release that footage. The two suspects are said to have placed the bombs in their locations mere minutes before the explosions.

The suspects are considered to be armed and extremely dangerous.

Boston bombing suspects, FBI