A Kansas board has approved a temporary rule requiring county election officials to throw out thousands of votes cast in state and local races by people who have registered without providing proof of their U.S. citizenship.

The State Rules and Regulations Board’s action Tuesday came only a day before Kansas opens advance voting for its Aug. 2 primary.

The rule was sought by Secretary of State Kris Kobach and will be in effect for 120 days, through the Nov. 8 general election.

The affected voters registered at motor vehicle offices without providing citizenship papers as required by a 2013 state law. About 17,000 are in that category.

A federal judge ruled in May that federal law requires the state to register them as voters for federal races.