Two people were killed and two others injured Wednesday afternoon in an explosion at a gas station east of Lewiston in Clearwater County, according to the Idaho Department of Insurance.

Two fatalities were found at the scene in Cardiff, while the injured were taken to hospital, a spokesman said.

“It is too early to speculate on the cause of this tragic event,” said Idaho State Fire Marshal Knute Sandahl. “It could take weeks to piece together the events leading up to the explosion and fire. We must be methodical and thorough.”

Dramatic photos released on Wednesday show large black smoke rising from orange flames at the scene.

According to the Idaho Department of Insurance, investigators are searching through the debris and looking for more victims. However, the amount of fuel at the scene has been a hindrance for investigators, according to a news release.

The National Transport Safety Board and the Occupational Safety and Health Agency are assisting in the investigation, the release said.