4-year-old Cella McDowell and her 2-year-old brother Chi were found with their parents around 1 a.m. Tuesday by police in Delaware.
The children live with their paternal grandparents in Virginia but were spending the week in the Bronx with their maternal grandparents.
Family members say that's when their parents showed up without warning and left with the children.
"And in a split second they just took them," said their aunt Tereen Beretervide. "She made us think everything was OK and everything was fine, she was fine with just visiting and she just manipulated us and that's it."
It was not immediately clear if the parents will face charges.
The incident was first reported on Grace Avenue around 6 p.m. on Monday.
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