ATLANTA (AP) — A federal grand jury indicted two men on charges they were part of a long-running scheme to defraud Delta Airlines.

The U.S. attorney's office in Atlanta says Michael Yedor of Los Angeles and Paul Anderson of Apple Valley, Minnesota, were indicted June 10. It wasn't immediately clear if they had lawyers.

Prosecutors say Anderson had worked for Northwest Airlines, which was bought by Delta in 2008, since 1979.

The indictment says Anderson submitted false invoices from a company owned by Yedor seeking payment for goods and services that were never provided. The indictment says the alleged scheme caused Northwest and then Delta to issue about $22 million in payments between 2004 and 2013.

Yedor and Anderson face charge of conspiracy to commit mail fraud and ninety-six counts of mail fraud.