9 charged in thefts of Yogi Berra rings, Warhol and Pollock paintings, other rare items: Feds

Nine people in Pennsylvania have been charged in connection with an alleged conspiracy to steal major artworks and sports memorabilia worth millions of dollars, U.S. prosecutors said.

The alleged heists spanned over 20 years and included the theft of championship rings, paintings, trophies and more, the U.S. Attorney's Office for the Middle District of Pennsylvania said in a statement.

A federal grand jury indicted Nicholas Dombek, 53, Damien Boland, 47, Alfred Atsus, 47, and Joseph Atsus, 48, on charges of conspiracy to commit theft of major artwork, concealment or disposal of objects of cultural heritage and interstate transportation of stolen property, the U.S. attorney's office said.

Five others were charged by felony information in connection with the alleged conspiracy.

An attorney for Boland declined comment. Attorneys for Dombek and Alfred and Joseph Atsus did not immediately respond to ABC News' requests for comment.

Eight of the nine people accused of participating in the theft ring have surrendered, U.S. Attorney Gerard M. Karam said during a press conference on Thursday. Dombek is considered a fugitive and has not yet been located by authorities, he said.

According to the indictment, the suspects allegedly transported the stolen items back to Dombek's home in northeast Pennsylvania, where the metal items were melted down into transportable bricks and discs.

The raw metal was collected in hopes of being sold for hundreds of thousands of dollars -- significantly less than market value if the items were left in their original forms, the indictment says.

The thieves' haul includes 9 World Series rings and two MVP plaques awarded to Yogi Berra that were stolen in 2014 from the Yogi Berra Museum & Learning Center in Little Falls, New Jersey, according to the indictment.

The long list of items allegedly stolen also includes the paintings "La Grande Passion" by Andy Warhol and "Springs Winter" by Jackson Pollock, stolen in 2005 from the Everhart Museum in Scranton, Pennsylvania; six championship belts from the International Boxing Hall of Fame in Canastota, New York; and five trophies worth over $400,000 stolen in 2013 from the National Racing Museum & Hall of Fame in Saratoga Springs, New York.

The indictment alleges that Dombek burned the painting "Upper Hudson" by Jasper Cropsey, valued at approximately $500,000, to avoid its recovery by investigators for use as evidence against the members of the conspiracy.

The whereabouts of many other paintings and stolen objects are currently unknown, authorities say.

ABC News' Luke Barr, Devani Allen and Sherby Perez contributed to this report.