A 1.7-magnitude earthquake caused the rumbling reported by dozens in Northeast Philadelphia late Friday, the U.S. Geological Survey said Saturday. No significant damage was reported.

The microtemblor, which some said could be felt as far away as Bensalem, struck just after 9:30 p.m. with an epicenter just blocks from the Franklin Mills Mall.

Government seismologists had said Friday that an earthquake was not to blame for the boom reported by residents near the intersection of Knights and Fairdale Roads, but they revised their findings on their website Saturday.

Friday's quake was the second in the Philadelphia region this month. The Geological Survey recorded a 1.9-magnitude disturbance May 10 in Westampton. - Jeremy Roebuck