BOSTON (REUTERS) - The FBI said on Thursday that "identifying and locating those responsible is now our highest priority," after officials showed the public pictures of two men seen near the Boston Marathon bombing on Monday.

The two men are seen on videotapes and the FBI said that suspect No. 1 is wearing a dark hat while suspect No. 2 has a white hat. The second suspect was seen planting the bag that eventually exploded, the FBI said at news conference in Boston.