Police are hunting a man who they say forced his way into a hotel room and took his two young children from their mother.
Saleem Tahir took Nallah Khan, two, and Sulailman Khan, 10 months, from a hotel in Hanley, Stoke-on-Trent, at about 17:00 BST on Friday, officers said.
Police said the children were believed to be with their grandmother Denise Smith-Sellers, 67.
Saleem Tahir is originally from the Nottingham
They were last seen in the Selly Oak area of Birmingham on Saturday evening.
A Staffordshire Police spokesman said: "The children were taken by their father, 40-year-old Saleem Tahir, who is originally from the Nottingham area."
Officers have urged anyone with information to contact the force.