Updated

Authorities have launched a criminal homicide investigation into the house explosion that killed two people and damaged numerous homes in an Indianapolis neighborhood.

Indianapolis Homeland Security Director Gary Coons made the announcement Monday evening.

Marion County Prosecutor Terry Curry says search warrants are being executed and that official are looking for a white van that was seen in the neighborhood.

Officials have said they believe natural gas was involved in Nov. 10 explosion, which leveled two homes and left dozens more uninhabitable. Investigators have been focusing on appliances as they search for a cause.

Funerals were held earlier Monday for the couple killed in the explosion, 34-year-old John Dion Longworth and 36-year-old Jennifer Longworth. They lived next door to the home where investigators believe the explosion originated.