A 10-hour police standoff with a man who had barricaded himself in a house in Fairfax County, ended without injury Sunday afternoon when the suspect surrendered, authorities said.

Fairfax County Police said the man, believed to be armed, barricaded himself in a house in Herndon just after 4 a.m. Authorities said the man threatened to kill family members and to shoot officers sent to respond.

The family escaped, but the man remained inside the house. A heavy police presence amassed in the 13200 block of Ladybank Lane in Herndon. Police said they heard “what sounded like” a gunshot about 6 a.m.

“We have had contact with the man since, but the barricade continues,” Fairfax police said in an early-morning tweet. “Please avoid the area.”

The neighborhood was blocked off to vehicle traffic at Stone Heather Drive and Stone Heather Court, about a third of a mile down the road.

Shortly after 2 p.m., police said the standoff had ended. Additional details, including the suspect’s identity, were not immediately available.