WHITEFISH TOWNSHIP, Mich. (AP) — A registered sex offender and another man have been arrested on kidnapping and other charges while trying to cross an icy Lake Superior in Michigan’s Upper Peninsula with the sex offender’s 5-year-old son.

The Chippewa County sheriff’s office says 53-year-old George Cunningham and 68-year-old Jon Stygler were caught early Thursday about two miles out from Whitefish Point and about 15 miles from the Canadian mainland.

Officers tracked them with snowmobiles after two adults and several children were bound at knifepoint before the boy was taken from a home in Whitefish Township.

An Amber Alert was issued for the boy.

Cunningham and Stygler were arraigned Thursday. Michigan State Police sex offender records show Cunningham was convicted in 2015 in Ohio on charges involving a child younger than 13.

Both men are due in court March 25. Neither had defense attorneys Thursday.