FRIDLEY, Minn. (AP) _ Two young sisters were burned, one critically, when a van caught fire in a Walmart parking in a northern Minneapolis suburb.

Authorities say the girls were alone in the van Tuesday morning for 45 minutes to an hour as their mother shopped in the store in Fridley. A van next to the girls' van caught fire around 7:15 a.m., and the blaze spread to the girls' van.

Fridley police Lt. Jim Mork says a 6-year-old girl suffered critical burns. Her 9-year-old sister suffered less serious burns. The Star Tribune reports both were taken by ambulance to HCMC.

Mork says the girls' mother was ``hysterical.'' He says the fire is not considered suspicious.

A woman sitting in the first van that burned escaped without injury.