ALBANY, N.Y. (CBSNewYork/AP) – Federal authorities have filed additional charges against a northern New York couple accused of kidnapping and sexually abusing two young Amish girls in August.

U.S. Attorney Richard Hartunian says Wednesday the case against 39-year-old Stephen Howells and 25-year-old Nicole Vaisey of Hermon now involves six child victims. They had previously been charged with crimes against three, including the Amish girls released after being held for a day.

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The two sisters vanished Wednesday evening in Oswegatchie, touching off a massive search in the farming community near the Canadian border. They turned up safe Thursday night at the door of a house 15 miles from their home.

The new 21-count indictment had not been filed as of early Wednesday evening, but Hartunian says both face charges they exploited three children between last September and August. Howells is additionally charged with six counts involving four children at other times.

Howells is also charged with five new counts of possessing child pornography.

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Both previously pleaded not guilty. Vaisey’s lawyer declined to comment. Howell’s could not be reached.

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