NEW DELHI: An earthquake measuring 5.1 on the Richter Scale struck Morigaon district in Assam early Monday morning, the National Centre for Seismology (NCS) said. The tremor occurred at 04:17:40 IST, with its epicentre located at latitude 26.37 N and longitude 92.29 E, at a depth of 50 km. There were no immediate reports of casualties or damage to property, officials said, though residents reported feeling mild to moderate tremors in parts of central Assam. Authorities are monitoring the situation.