A teenager in Oregon planned to set off an explosive at a shopping mall in Washington state and shoot people as they fled the movie theater there, said law enforcement officials, one of whom said the plot "was as serious as it gets.

The FBI and local authorities arrested a teen who allegedly planned a mass shooting with improvised explosives at a Washington state shopping mall.

The FBI derailed a plot by a teenager who had planned to detonate a bomb at a Washington state shopping mall and shoot people as they fled a movie theater in the building, law enforcement authorities announced Thursday.