Arlington, Virginia, officers were investigating shots fired and executing a search warrant when a house exploded.
The large explosion did not kill anyone, and authorities reported no significant injuries.
U.S. Rep. Don Beyer called the explosion a "major explosion" that smashed windows, was audible for miles, and forced neighbors to evacuate.
On X (previously Twitter), Congressman Beyer called the bomb "very very scary".
Witnesses reported a "enormous" explosion, shaking houses and scattering broken glass.
Police received a complaint at 4:45 p.m. about a flare gun being shot at a Burlington Street home.
The suspect inside the house refused to cooperate, so police tried calling and loudspeakering before serving the warrant.
The house exploded at 8:25 p.m. as police arrived after the suspect fired several shots from a weapon inside.