A tremor measuring 4.1 on the Richter scale shook the vicinity of Siah Cheshmeh in the northwestern province of West Azarbaijan Friday night. According to the seismological base of the Geophysics Institute of Tehran University, the tremor occurred at 20:13 hours local time (1543 GMT). The quake was epicentered in an area located at 39.20 degrees latitude and 43.67 degrees longitude. There is no report on possible damage caused by the earthquake.