Dozens of Fairfax County firefighters responded to a large fire early Monday morning that tore through a house in Annandale, Virginia.

Initial 911 calls from neighbors just before 4 a.m. reported the sound of an explosion along with the fire in the 4200 block of Ann Fitz Hugh Drive. However, fire officials later said, so far, they haven’t found any signs of a explosion at the Wakefield-area house.

No one was inside the house when it caught fire, according to the fire department.

Some neighbors told WTOP the sound of a blast “rocked the neighborhood,” which is nestled in in a wooded area near Little River Turnpike.

“It wasn’t just a pop, it was a very long explosion,” said neighbor Meredith Hedrick. “It almost sounded like a siren.”

One neighbor told WTOP he looked out his window and saw the house “engulfed” in flames and and nearby trees were on fire.

Flames were seen billowing from the roof as the fire spread to multiple floors of the three-story house and the entire roof was burned out.

The fire department said a second alarm was declared as firefighters battled the flames, and the fire was severe enough that crews had to evacuate the house and fight the fire from the outside, according to Fairfax County Fire and Rescue Deputy Chief Greg Hunter.

The fire was under control as of shortly before 5:30 a.m.

No firefighters were hurt battling the fire.

Officials are still working to determine the cause of the fire.

WTOP’s Luke Lukert contributed to this report from Annandale, Virginia.