Washington (AP) — Homeland Security Secretary Janet Napolitano says the FBI wants to speak with two men seen in at least one video from the Boston Marathon, but she says she isn't calling them suspects.

Without providing details of the men's appearance or what the video shows, Napolitano told the House Homeland Security Committee on Thursday that "there is some video that raised the question" of two men the FBI would like to interview but said she wouldn't described them as suspects.

Napolitano said it's still unclear whether the bombs that exploded near the finish line of the Boston Marathon were the work of foreign or domestic terrorists. She said the investigation is continuing "apace."

Three people were killed and more than 170 others were injured when the bombs exploded Monday.