The FBI has 850 open domestic terrorism investigations, 40% of which are cases of racially motivated violent extremism, Assistant Director for Counterterrorism Michael McGarrity said Wednesday.

Testifying before the House Homeland Security Committee, McGarrity said a "significant majority" of those racially motivated cases involved white supremacist extremists, and he called the threat posed by domestic terrorists in the US "persistent and evolving."

"The FBI assesses domestic terrorists collectively pose a persistent and evolving threat of violence and economic harm to the United States. In fact, there have been more arrests and deaths in the United States caused by domestic terrorists than international terrorists in recent years," McGarrity said.

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