The incident was dubbed as a criminal incident and drew a huge response from local and federal law enforcement, reported ABC News.

Describing the incident as an isolated incident, the authorities in a press conference on Sunday revealed that the investigators believed that the perpetrator was one of three men who was killed in the explosion.

The cause of the accident is still unknown.

The Federal Bureau of Investigation (FBI) and the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) are among the agencies investigating the case.

The authorities have sealed off the area surrounding the explosion. (ANI)