Philadelphia residents who were shocked to feel their homes shake from what they thought was an explosion learned Saturday that a minor earthquake had struck the area.

An earthquake registering magnitude 1.7 struck the Philadelphia area Friday night, the US Geological Service (USGS) said Saturday.

The quake struck at 9:33pm local time Friday in northeastern Philadelphia at a shallow depth of 2.6 miles (4.2 kilometers).

The USGS initially said it had no seismological evidence of an earthquake or tremor as officials had no explanation earlier Saturday for residents who felt their homes rumble, The Philadelphia Inquirer reported.

Police, firefighters and other emergency responders were dispatched to the area after hundreds of residents reported feeling the ground shake shortly before 10:00pm.

Resident Edward Turzanski described hearing "a loud bang," then feeling "a sharp jolt from below."

No fires, explosions damaged homes or injuries were found.

A representative for power company Peco Energy said there were no reports of power outages, and the Philadelphia Water Company said there was no evidence that any pipes had burst, the paper said.

The Philadelphia Fire Department declared the situation to be under control at 10:45pm, and emergency crews left the area around 11:30pm.

The quake was also felt in lower Bucks County, Pa., about 50 miles (80 kilometers) north of Philadelphia, according to the report.