Security threat

U.S. intelligence chief warns of 'homegrown' security threat

Attacks by "homegrown" Islamist extremists are among the most imminent security threats facing the United States in 2016, along with dangers posed overseas by Islamic State and cyber security concerns, the top U.S. intelligence official said on Tuesday.

In his annual assessment of threats to the United States, Director of National Intelligence James Clapper warned that fast-moving cyber and technological advances "could lead to widespread vulnerabilities in civilian infrastructures and U.S. government systems."

In prepared testimony before the Senate Armed Services and Intelligence Committees, Clapper outlined an array of other threats from Russia and North Korean nuclear ambitions to instability caused by the Syrian migrant crisis.