A man arrested on suspicion of arson in a large wildfire in Spokane, Washington, was previously linked to two other fire investigations last year.
Aaron Farinacci, 37, was allegedly seen kneeling near grass at the site of the latest blaze and was later found to have matches and a lighter, the Spokane County Sheriff said.
The fire is the largest of three burning around the north-western US state’s second-most-populous city, forcing more than 60,000 people to evacuate and destroying more than 700 buildings.
None of the fires has been contained near Spokane, a city of some 230,000 people about 280 miles (450 km) east of Seattle.
Washington Governor Bob Ferguson said it was a “nightmare situation”, adding: “This is likely the worst natural disaster in Spokane history.”
No deaths or injuries have been confirmed.
But the city’s mayor Lisa Brown said there was still “the potential for lives to be lost”.
Authorities are trying to make contact with 14 people they have been unable to reach by mobile phone, but are not yet considered missing.
Sheriff John Nowels said it was likely many of them did leave but had lost signal or had depleted phone batteries.
The three fires in the city – Old Trails, Fairview and Autumn Lane – are among a total of 16 wildfires in Washington state, according to the state’s department of natural resources.
Firefighters have made progress against two of them, but while Tuesday saw lighter winds and cooler weather, temperatures could rise again later this week.
Farinacci, who was arrested over the Old Trails fire, was being held on a charge of arson in the first degree. He was held on a $1m (£744,000) bond.
He appeared in court on Tuesday via video call, but did not enter a plea to the charge.
Residents reported seeing Farinacci near some train tracks before they saw flames in the area, according to charging documents.
Authorities stopped Farinacci near the scene. He was found with a pack of cigarettes, a butane lighter and a box of what authorities called “heavy duty waterproof matches”, say the court papers.