Two wildfires raging overnight on Montana's Blackfeet Indian Reservation burned thousands of acres, forced scores to evacuate and destroyed several buildings, officials said early Thursday.

Fueled by strong winds, the two blazes started around sundown Wednesday and together had grown to at least 45,000 acres by 4 a.m. MST Thursday. At least 300 people were forced to leave their homes and a school, and officers were working to evacuate additional residents in the fires' eastward path.

No injuries have been reported.

Browning residents said the fires illuminated the sky and created to a chaotic scene as the city's streets were flooded with emergency vehicles and people unsure of what was happening.

"You could see flames all around on the east side of Browning, they were very clear and bright," said Browning resident Gabe Renville. "It was chaos. It was a danger to be out. There was traffic and flashing lights and I was afraid somebody was going to get run over."

One fire started southeast of Browning around sunset and burned about eight miles east to the community of Blackfoot, tribal spokesman Wayne Smith said. Another blaze erupted around the same time about 10 miles away.

A blaze called the Y-fire has scorched at least 30,000 acres and was about 50 percent contained, Smith said.

The nearby Boy Fire had burned through about 15,000 acres of grasslands. He didn't have a containment estimate.

"It's probably the biggest grass fire in reservation history," Smith told The Associated Press.

About 200 residents and students were evacuated from an area north of Browning known on Boarding School Road, where there is a boarding school, while another 100 people from two Hutterite communities were evacuated to the Cut Bank Civic Center about 35 miles east of Browning.

Renville said his 12-year-old daughter, who attends the school, sent him a text message at 5:30 p.m. Wednesday saying there was a fire near the school. Buses were sent and the school's staff used their personal vehicles to evacuate more than 60 students and bring them to the Blackfeet tribal offices in Browning, where their parents picked them up, Renville said.

The Hutterites arrived in Cut Bank about 9:30 p.m. Wednesday and remained until after 1 a.m., when U.S. Highway 2 reopened, said Jennifer Biegler, Cut Bank's parks and recreation director. Volunteers and local officials brought blankets, food, water and coffee for the evacuees.

"They were hungry and worried and nervous and anxious," Biegler said. "We knew there was a fire, but we first heard it was way by Browning. The next thing we knew, it was 14 miles from town."

Biegler said the civic center remained on standby in case of more evacuations as the fires continued spread.

"Local police, fire and EMS crews are everywhere. Responding where they are able to," tweeted Shannon James Augare, a state senator from Browning. "Please keep these individuals in your prayers."

Blackfeet Law Enforcement Chief Greg Gilham told the Great Falls Tribune that the fires were started by what was believed to be power lines that were blown over by high winds. One fire that burned east of Browning had already been put out.

"We're just in the middle of trying to evacuate houses that are in the way of the grass fire," Gilham said.

Smith said the fires were being pushed eastward by winds of 30-40 mph.

National Weather Service meteorologist Chris Zelzer in Great Falls said a 61 mph wind gust was recorded in Cut Bank just before 6 p.m. Wednesday, and a 72 mph gust was recorded in Heart Butte south of Browning a few minutes later.

"There's a lot of reports in that range," he said.

Zelzer added that windy conditions were expected to continue through the night as a disturbance moves over the mountains.

"Sustained winds in that area, at least along the slopes of the Rockies, will stay pretty high," he said.

However, Smith said early Thursday that he had heard the winds cold ease somewhat during the day.

The northwest Montana reservation is east of Glacier National Park and borders Canada.