NEW YORK — Fast-moving brush fires fanned by high winds burned through a large swath of land on New York’s Long Island on Saturday, spewing thick gray smoke into the sky and prompting the evacuation of a military base and the closure of a major highway.

Gov. Kathy Hochul declared a state of emergency and said state agencies were responding to the fires around the Pine Barrens, a wooded area that is home to commuter towns east of New York City. She said homes, a chemical factory and an Amazon warehouse were at risk and more evacuations may be needed.

“This is still out of control at this moment,” Hochul told Long Island TV station News 12. “We’re seeing people having to be evacuated from the Westhampton area.”

Officials said three of the four fires were fully contained, with the fire in Westhampton 50% contained. Two commercial buildings were partially burned, but officials said homes were not in the line of fire.

One firefighter was flown to a hospital to be treated for burns to the face.

“Our biggest problem is the wind,” Suffolk County Executive Ed Romaine said. “It is driving this fire.”

Videos posted to social media showed flames shooting into the air and columns of black smoke rising above roads.

Air National Guard helicopters dropped water on the flames.

The Town of Southampton issued a warning in the afternoon against starting recreational fires due to the wildfire risk. That came around the time that the videos began appearing.

In a statement, Hochul said the National Guard was providing support by helicopter and working with local law enforcement.

“Public safety is my top priority, and I’m committed to doing everything possible to keep Long Islanders safe,” she said.

In her comments to News 12, Hochul declined to estimate the extent of the flames, saying only that they were growing rapidly.

Rough satellite data indicated that fire and smoke stretched roughly 2.5 miles (3 kilometers) along Sunrise Highway, according to NASA’s Fire Information for Resource Management System.

Police closed a section of the highway, which is a thoroughfare to the East End of Long Island.

The fires raged near the Francis S. Gabreski Airport, from which the National Guard launched at least one helicopter. One of the commercial buildings that partially burned was near the airport.

Personnel at the base evacuated as a precautionary measure starting around 1:45 p.m., spokesman Cheran Cambell said in a statement.