A wildfire in the Great Dismal Swamp National Wildlife Refuge has spread to about 200 acres, refuge director Chris Lowie said Saturday afternoon.

The fires were first reported Thursday night when a plane flying home from fighting a North Carolina wildfire spotted the smoke, but it’s unknown how long they could have been burning before that. One was initially estimated at 15 acres, and the other was confined to a single tree.

The tree fire has not spread, Lowie said Saturday, but the larger fire has grown more than 13 times larger than the initial estimate.

“Things are going very well,” Lowie said. “It is staying within the lines we’re building, but I don’t believe those lines are complete yet.”

Lightning has been determined as the most likely cause of the fires. Lowie said Friday that the National Weather Service reported strikes in the area recently. He said there is no work being done near the fires and they are about a mile from public access.

Residents to the west of the refuge were affected by smoke on Friday, but a wind shift on Saturday brought the smoke to downtown Suffolk and other areas.

Additional people and equipment are on their way to the refuge to help fight the fire, Lowie said.

Because of the fires, Railroad Ditch Road and trail are closed until further notice.

For more information on the refuge, call 986-3705.