SAN BRUNO, Calif. -- A city spokesman says authorities are now unsure whether remains found at the suburban San Francisco blast that destroyed nearly 40 homes belonged to the two people reported missing since the explosion and fire.

San Bruno spokesman Steve Firpo says the remains were found Saturday morning, but could be those of four people already reported dead.

Firpo said earlier Saturday that the discovery brought the death toll in Thursday's blast to six people. He says officials now can only confirm that four died.

The San Mateo County Coroner's office said 44-year-old Jacqueline Greig, her daughter 13-year-old Janessa, and 20-year-old Jessica Morales were killed in the fire. One other victim found earlier has yet to be identified.