Ten more members of Congress are joining a lawsuit against former President Donald Trump over the Jan. 6 riot at the U.S. Capitol, alleging that he and others violated federal law in inciting the attack during the certification of the Electoral College count.

The lawmakers—all Democrats in the U.S. House of Representatives—are adding their names to the lawsuit initially filed by Rep. Bennie Thompson in February. Lawyers with Cohen Milstein Sellers & Toll and the NAACP are representing the members in the suit, alleging Trump violated the Ku Klux Klan Act of 1871 in acting to block the certification of the election results.