FORT DODGE, Iowa — Four people, including a seven-year-old child, were injured by a butane explosion inside a vehicle parked outside a tobacco and vape business in Fort Dodge on Saturday.

According to a news release, the Fort Dodge Fire Department was called to World Liquor & Tobacco + Vape on N. 15th Street at 3:24pm on a report of a vehicle explosion with four people injured. Firefighters arrived to find the car still burning. Four people were injured in the explosion. Two of them – a 21 year old woman and a seven year old boy – were airlifted to a burn unit in Iowa City. A 24 year old man was taken there by ground ambulance as well. A fourth victim suffered just minor injuries. Their names have not been releaseD.

Police say the fire was caused by someone in the vehicle “using butane” while when another occupant lit a lighter, igniting the fumes. The Fort Dodge Police and Fire departments are both investigating still.