According to the National Centre for Seismology (NCS) data, the tremor struck at a depth of 40 km from the surface. Within 49 minutes from the first tremor, another quake measuring 3.3 on the Richter scale, hit Churachandpur district and adjoining areas at around 9.46 p.m. The second shake struck at a depth of 30 km from the surface, the NCS data said.