Click here to view FBI photos, video of Boston bombing suspects.
The FBI has released photos of two suspects in the Boston Marathon bombings and is asking for the public's help in identifying them.
FBI Agent Richard DesLauriers said Thursday afternoon the photos came from surveillance cameras near the explosion sites. Both men were carrying backpacks. One is seen wearing a dark baseball cap, the other a white cap worn backwards. DesLauriers said the man in the white cap was seen setting down a backpack at the site of one of the blasts, which killed three people and injured more than 180 on Monday.
DesLauriers said one the suspects is believed to have planted the devices outside of a restaurant near the finish line. He said both suspects are considered armed and extremely dangerous and people who see them should not approach them.
Anyone with information is encouraged to call 800-CALL-FBI. Online tips can be forwarded to bostonmarathontips.fbi.gov.
Those injured in the bombings received a visit from President Obama and first lady Michelle Obama on Thursday. After he attended an interfaith church service in honor of the dead and wounded, Obama went to Massachusetts General Hospital where he met privately with patients, their families and staff.
The Obamas met earlier at the church with the family of Krystle Campbell, one of the three killed.
At the church service, Obama vowed to hunt down those responsible for the twin blasts. You will face justice." If the bomber or bombers were hoping to "intimidate" or "terrorize" Americans, Obama said they "picked the wrong city to do it." Like the marathoners themselves, Obama said, "We may be momentarily knocked off our feet," but that "we'll pick ourselves up."