INDIANAPOLIS (AP) - The house explosion that killed two people and destroyed several Indianapolis homes is now a homicide investigation.

Indianapolis Homeland Security Director Gary Coons made the announcement Monday, marking the first time investigators are acknowledging a possible criminal element in the Nov. 10 blast.

No suspects have been named. Officials believe natural gas was involved in the explosion, which destroyed five homes and left dozens more damaged.

The funeral for the couple killed in the blast, Jennifer and John Dion Longworth, was held earlier Monday. The couple lived next door to the house where investigators believe the blast occurred.

No one was in the other home during the explosion. The man and woman living there were at a casino, the woman's daughter was with friends, and their cat was being boarded.

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