The FBI has "identified a person of interest in what [it is] calling a case of domestic terrorism" in Jefferson County, Colo., just two miles from Columbine High School, Denver's KUSA-TV reports.
And, the station adds, "the fact that [a] pipe bomb and propane tanks were found on the 12th anniversary of the shootings at Columbine High School is not lost on investigators."
The devices were discovered in a shopping mall about two miles from the school where, on April 20, 1999, two students killed 12 other teens and one teacher before turning their guns on themselves. They were found after a small fire broke out in a service hallway, The Denver Post says.
The "person of interest" — an older man with gray hair, as the Post reports — can be seen in video surveillance. Authorities released a frame grab from that tape in the hope that someone will recognize the man or he will come forward.