Passersby stopped to pull people from the burning vehicle Saturday evening along I-85 near the I-985 split, Gwinnett County police Sgt. Michele Pihera said in a news release. The area is about 35 miles (56 kilometers) northeast of downtown Atlanta.

Six people were pronounced dead at the scene and several others were taken to Atlanta-area hospitals for treatment. One bystander suffered a minor injury but declined to be transported, police said.

It was unclear how many people were inside the van but police believe all were adults. The news release said details about the people in the van would be announced in the coming days.

Investigators were working to determine the cause of the crash. Information at the scene led police to believe another vehicle may have been involved. Witnesses were asked to call the police department's accident investigation tip line with any information.