A nine-year-old B.C. girl who was the subject of an Amber Alert Monday has been found safe in the U.S., according to officials.

Bellingham police said the child was in "protective custody," and her mother had been arrested for custodial interference.

Female suspect in custody for custodial interference 1. Minor female is safe and in protective custody. —@BellinghamPD

Police in New Westminster, B.C. issued an Amber Alert for the nine-year-old earlier Monday. Police say they believe the 48-year-old mother took her daughter after a custody visit — violating a court order — and crossed the border into the U.S.

The pair was found at a Bellingham church on Monday afternoon, after the mother's car was found outside a Coachman Inn.

"At this point, we do not know the purpose of violating the court order," said New Westminster police spokesman Sgt. Jeff Scott.

With files from The Canadian Press