Brothers found after national search alert
The boys disappeared after going on a bike ride to a local park, sparking a UK-wide search.
Northumbria Police said a total of seven people had been arrested in connection with the case.
Two men, aged 47 and 22, and a 23-year-old woman were arrested in Lancashire earlier.
A 37-year-old man was arrested in London and another man, aged 41, was arrested in Newcastle, on Thursday evening.
Officers are continuing to question a 34-year-old man and a woman of 39, arrested in Birmingham on Wednesday.