About two dozen people and firefighters were injured on Wednesday in an explosion and fire that erupted at an apartment building north of Washington D.C., a spokesman for the fire services said.

The explosion shortly before midnight rocked Silver Spring, Maryland, and the fire burned into Thursday morning, Pete Piringer, a spokesman for the Montgomery County Fire and Rescue Service, said on a voice recording.

Authorities were investigating the cause of the explosion.

Piringer tweeted that about two dozen people, including firefighters, were injured. He did not say whether anyone was killed.

The Montgomery County Fire and Rescue Service said the fire was under control.