Additional water tankers and scores of firefighters arrived at the Los Angeles area on Monday ahead of fierce winds that were forecast to return and threaten the progress made so far on two massive infernos that have destroyed thousands of homes and killed at least 24 people.

Mandatory evacuations for more than 100,000 people remain in place for the wildfires, which started Jan. 7 amid a powerful windstorm that forecasters warned would be the worst the region has seen in more than a decade.