Police say the woman alleged to have abducted her two children in British Columbia may also be travelling with two men, likely her father and boyfriend.
Surrey RCMP spokeswoman Cpl. Vanessa Munn says police have seen images from Merritt, B.C., on July 7 showing Verity Bolton with the two men along with her children, eight-year-old Aurora and 10-year-old Joshuah Bolton.
Munn says police believe the two men are Verity Bolton's father, 74-year-old Robert Bolton, and boyfriend Abraxas Glazov, 53.
July 7 was the last time the children were seen, and police say their mother was spotted by closed-circuit TV emerging from a grocery store in Kamloops on July 15, two days before she was expected to give her children back to their father after a vacation.
The children live in Surrey with their father and were the subject of an Amber Alert on Wednesday, when police said they have concerns about both the mother's mental health and the children's well-being.
RCMP say in a news release that its serious crimes unit has taken over conduct of the investigation, and there is no evidence to indicate that the group has left British Columbia.
A photo released by RCMP shows a blue 2012 Dodge Ram 2500 pickup, towing a white horse trailer, that the woman is believed to be driving, and anyone who sees the vehicle or the Boltons is urged to call 911.
Police say the Amber Alert has generated a large amount of tips, and investigators are sorting through the information to put together a timeline of events to help find the missing children.