A mother who was reported missing with her two sons is wanted by police on suspicion of abduction.
Samantha Baldwin, 42, from Newark, was last seen near Nottingham city centre on Monday.
Police believe she is with sons Dylan Madge, six, and Louis Madge, nine, who she does not have legal custody of.
A Nottinghamshire Police spokesman said two women, aged 62 and 36, had been arrested on suspicion of assisting an offender and remained in custody.
Superintendent Rich Fretwell said "An investigation into the circumstances is well under way and we have a large amount of resources working around the clock to locate Dylan and Louis.
"Our priority at the moment is to locate them safe and well.
"We are now appealing for the return of Dylan and Louis and any information about the whereabouts of them and their mother, Samantha."
Police had issued a missing person appeal for Mrs Baldwin and the two children on Tuesday.
Ms Baldwin is described as 5ft 7in, of slim build with shoulder length, highlighted blonde hair and green/blue eyes.
She was last seen wearing a red knee-length coat from Mango but may have changed her clothing since.
Louis has collar-length straight fair hair, a fair complexion and blue eyes, while Dylan has collar-length straight dark brown hair, a tanned complexion and brown eyes.
Anyone with information should call Nottinghamshire Police on 101 urgently, quoting incident number 332 of 27 March 2017.