Update 11:30 a.m. Friday:

Officials believe the wildfire that closed the Seward Highway for two hours Thursday night near Indian was sparked by a backfiring vehicle.

Alaska Division of Forestry spokesman Norm McDonald said the 2-acre fire's exact cause has not been determined but is suspected to be similar to that of four smaller Mat-Su wildfires earlier Thursday. Those blazes were tracked to backfires from a white Chevrolet pickup truck; its driver was stopped but not cited by Alaska State Troopers.

"We think the probable cause was an exhaust issue off a truck," McDonald said. "That vehicle was found; the one on the Seward Highway was not."

The fire has been contained and controlled, McDonald said, and will be monitored through the weekend for flare-ups.

McDonald asked people to be aware of dry conditions conducive to wildfires, particularly in the Mat-Su, where permits for open burning are now required. People can call a burn permit hotline at 907-761-6312 for the status of fire regulations in the region.

"Just be vigilant if you're doing any burning, and call in daily to make sure we don't close it down if there's different winds and diff conditions," McDonald said.

Original story:

The Seward Highway was closed for about two hours Thursday evening as firefighters battled a wildfire near the community of Indian, the Anchorage Fire Department said.

Around 8:30 p.m., the northbound lane was reopened, said Jodie Hettrick, deputy chief of the fire department. By 10 p.m., the Seward Highway had fully reopened, according to an Anchorage Police Department dispatcher.

The blaze was reported to the fire department at 6:13 p.m. It was about 50 yards wide and 100 yards up a hill at Mile 105.5, just east of the Falls Creek Trail, in the Windy Corner area, Hettrick said.

By 7:45 p.m., the fire was mostly extinguished, Hettrick said. Anchorage police assisted with traffic, she said.

Anchorage firefighters remained on the scene until about 9 p.m., and then the Alaska Division of Forestry was set to take over the response, Hettrick said. Seven vehicles responded initially.

The cause wasn't yet known, Hettrick said.

A wildfire along the Seward Highway on Thursday, as seen from across Turnagain Arm near Hope. (Nathaniel Herz / Alaska Dispatch News)
A wildfire along the Seward Highway on Thursday, as seen from across Turnagain Arm near Hope. (Nathaniel Herz / Alaska Dispatch News)

Correction: An earlier version of this article incorrectly reported that the U.S. Forest Service would be taking over the response for Anchorage firefighters.