A multi-vehicle crash in downtown Gatlinburg, Tennessee, left at least seven people injured on Sunday, including two pedestrians, authorities said.

The crash happened around 4 p.m. after a minivan traveling southbound on Parkway "accelerated unexpectedly," hitting a pedestrian, according to an official with the Tennessee Department of Safety and Homeland Security.

In the process, the van struck several vehicles, resulting in a roadside sign falling and injuring a second pedestrian on the sidewalk, Special Agent Jason Pack reported.

A total of seven people were injured: five people inside two different cars and two pedestrians, according to Pack. Their identities and the extent of their injuries are not known at this time.

"Early indications suggest the possibility of a medical emergency contributing to the crash," Pack reported.

The case remains under investigation by the Tennessee Highway Patrol, with the assistance of its Critical Incident Response Team.

Three people were airlifted to the University of Tennessee Medical Center, while three others were taken to an area hospital, according to the NBC-affiliate, WBIR, in Knoxville.

This story was originally published by the Scripps News Group in Lexington, Kentucky.