Dr. John Ebel of the Weston Observatory in Massachusetts said the quake reported by some New Hampshire residents at about 4:35 p.m. Sunday was likely an aftershock from a 1727 earthquake in the Merrimack, N.H., area, WMUR-TV, Manchester, N.H., reported Tuesday.

Ebel said the original 5.6 magnitude quake caused numerous aftershocks in the area that have continued for nearly three centuries. He said the most recent confirmed aftershock took place in October 2007 and measured a 1.3 magnitude on the Richter scale.