An earthquake measuring 2.8 points on the Richter Scale, epicentred some 270 km to the east of Sofia within Bulgarian territory, was registered at 9:19 a.m. local time on Wednesday, BTA press agency announced. The tremor was felt weakly in Yambol Municipality (Southeastern Bulgaria). There are no reports of casualties and damage to property, Civil Protection said. `Weak aftershocks are normal for shallow earthquakes, occurring at a depth of 10-15 km,` Roumyana Glavcheva of the Geophysical Institute told BTA. Further light tremors are possible, considering the current sesmic activity in the Yambol area, she added. This is the third earthquake in the Yambol area within a week. The strongest tremor, 4.3 points on the Richter Scale on August 13, resulted in some minor structural damage but nobody was hurt.