An earthquake measuring 4 on the Richter scale rocked Assam and Nagaland Tuesday, triggering panic among residents. According to the Regional Seismological Centre in Meghalaya's capital Shillong, the tremor was felt at 12.26 p.m in most parts of Assam. No casualties were reported in the first 90 minutes after the quake. In Dimapur, the tremor was felt at around 12:25 pm. Students of Evershine School Dimapur at Riverbelt Colony were seen rushing down to the ground from the building in panic. The epicentre was located at Nagaon, 127 km east of Assam's main city Guwahati. In Assam, the tremor was felt in Guwahati, Nagaon, Tezpur and Jorhat, besides some other parts of eastern Assam. Seven NE states are considered by seismologists to be the sixth most earthquake-prone belt in the world.