LOS ANGELES — Repairs to an elevated Los Angeles freeway closed because of an arson fire are moving faster than expected and all lanes are scheduled to reopen by next Tuesday, Gov. Gavin Newsom said Thursday.

Earlier this week officials said it could take crews between three and five weeks to shore up the mile-long stretch of Interstate 10 near downtown after the blaze last Saturday burned about 100 support columns.

“The bridge structure itself seems to be in better shape than we anticipated,” Newsom said during an evening news conference. “One thing we can guarantee you is we will be open, five lanes in both directions, at the latest Tuesday of next week.”

More than 250 people were working around the clock to make the repairs, he said.

“This is a good day in Los Angeles,” Los Angeles Mayor Karen Bass said.

The fire that spread quickly over 8 acres was fed by pallets, cars, construction materials, hand sanitizer and other items being stored under the freeway in an industrial neighborhood. No injuries were reported, but at least 16 homeless people living in an encampment there were taken to shelters.

The arson investigation was ongoing, officials said. No arrests have been made and Newsom has said investigators are trying to determine if more than one person was involved.

An estimated 300,000 vehicles use the stretch of freeway daily, which runs east-west across the heart of the metropolis and connects with other major highways. The city has been urging people to avoid the area, take buses and trains, or work from home.