WASHINGTON (AP) — The FBI warned law enforcement agencies ahead of last week's breach of the U.S. Capitol about the potential for extremist-driven violence, U.S. officials said on Tuesday, contradicting earlier statements that they were caught off guard by the assault by supporters of President Donald Trump.

Nearly a week after the riot, officials said they were combing through mountains of evidence and vowed to aggressively seek out those who perpetrated the brazen attack on the U.S. Capitol. Though most of the charges brought so far have been misdemeanors, acting U.S. Attorney Michael Sherwi...