Butte County Sheriff Kory Honea announced search crews recovered seven more bodies in the Camp Fire burn area on Thursday, which brought the death toll to 63, according to The Los Angeles Times.
But said the number of those unaccounted for dramatically increased from 130 on Wednesday night to more than 630 people on Thursday.
Crews had found three bodies in Magalia, three in Paradise, and on in Concow.
The Camp Fire was still only 40% contained on Wednesday evening after burning through 141,000 acres and destroying more than 11,800 structures.
The fire nearly leveled the town of Paradise, with a population of 26,000, in several hours last Thursday so officials warned it could take weeks to complete the search for victims in the burn area.
Thousands of survivors are now spread throughout the state, living in shelters, tent cities, or out of their cars after losing their homes in the blaze.
Officials said the current search operation in and around Paradise was now the largest in California history, after the Camp Fire became the deadliest and costliest wildfire in the state's history.
Wendy Bailey, one of the search party members, told The Washington Post “We have never had anything of this magnitude. I have seen burned bodies before, but never just disintegrated. It’s usually not like this.”