ONTARIO, Calif. (AP) — Authorities sought Wednesday to identify the bodies of two people killed in a huge fireworks explosion in a Southern California neighborhood, saying they have not yet determined if the victims are two cousins reported missing since the blast. 

Tuesday's explosion, followed by two more, shattered windows up and down the block and left a vast debris field scattered over the neighborhood in Ontario, California.

Two dozen bomb technicians were searching for and removing unexploded fireworks in the debris to make the area safe for the eventual return of dozens of evacuated residents.

Enough unexploded fireworks to fill about 60 large buckets or boxes had been collected and were to be burned. But more explosives could be found and it could take days to clear the area, Ontario Fire Chief Ray Gayk said at a news briefing.

Though two people were killed in the explosion, the coroner's office has not yet been able to identify their bodies, which “weren't completely intact,” Ontario Police Chief Mike Lorenz said. The two bodies were discovered in the backyard of the property where the blasts began.

Reported missing are cousins Alex Paez, 38, and Ceasar Paez, 20. They have been associated with the property where the explosion occurred, but officials have not confirmed that they are the people who were killed.

Law enforcement agents — including the FBI — are investigating the explosion about 35 miles (55 kilometers) east of Los Angeles. A huge plume of smoke could be seen for miles. Two other explosions followed the main blast, and fireworks continued to explode hours after the initial explosion

Fire officials initially said the fireworks appeared to be commercial-grade, but Gayk on Wednesday said authorities had backed away from that description based on a closer look.

“Some of them are kind of a mixed bag of what you would find at out-of-state places” where they are legal, he said. 

Fireworks are illegal in Ontario, as in many California cities. Lorenz said last year, officers received more than 240 calls of fireworks being set off in the area.

The debris field encompasses 80 structures in the residential neighborhood, officials said.

Authorities said about 50 people had been placed temporarily in hotels.

There is still a “very significant chance” that more fireworks could explode, Lorenz said.

Authorities still have not been able to access the home where the explosion began.

“It’s too dangerous for us to get in there,” he said. “Today’s about making this place safe.”