WASHINGTON - Attorney General Jeff Sessions says he is unfamiliar with an FBI report about black "extremists" that is alarming some lawmakers.

The 12-page FBI intelligence assessment describes "black identity extremist" groups the FBI says are targeting law enforcement after police killings of black men. Foreign Policy first reported on the assessment, which drew outrage from some black lawmakers.

Democratic Rep. Karen Bass pressed Sessions on the report during a Tuesday oversight hearing before the House Judiciary Committee.

Sessions said he believed there were certain minority groups with the potential for violence. He struggled to answer when asked the same about white groups. He wouldn't say whether he considers Black Lives Matter an extremist group.

It was a tense exchange for Sessions, whose political career has been dogged by questions about race.