The 2002 Bou'in-Zahra earthquake (also known as the 2002 Avaj earthquake or the 2002 Changureh earthquake) occurred on 22 June 2002. The epicenter was near the city of Bou'in-Zahra in Qazvin Province, a region of northwestern Iran which is crossed by several major faults that is known for destructive earthquakes. The shock measured 6.5 on the scale, had a maximum Mercalli intensity of VIII (Severe), and was followed by more than 20 aftershocks. At least 230 people were killed and 1,500 more were injured. According to the International Institute of Earthquake Engineering and Seismology (IIEES), the earthquake was felt as far away as the capital city of Tehran, approximately east of the epicenter, although no damage was reported there. Most houses in the region were single-story masonry buildings, and virtually all of these collapsed. The public became angry due to the slow official response to victims who needed supplies. Residents of the town of Avaj resorted to throwing stones at the car of a government minister. Background and tectonics The northeastern part of Iran lies across part of the belt of active continental collision between the Arabian Plate and the Eurasian Plate. Iran is crossed by several major faults, with 90% of them being seismically active and subject to many earthquakes each year; the area around the rupture experiences minor quakes almost daily. The most seismically active parts of this area are the Zagros fold and thrust belt and the Alborz mountain range. Qazvin Province, which is located between these two zones, suffers less earthquakes, but these may be more powerful because stresses have longer to build. The Bou'in-Zahra earthquake was located in an area of active thrust faulting and folding, parallel and south of the southern edge of the Alborz mountain range, and was the 11th rupture in the previous two months in central Iran. A seismic inversion of long-period P and SH body-wave seismograms indicated a rupture on a thrust fault that dips 49 degrees to the southwest and had a centroid depth of roughly . The rupture's mechanism of faulting was reverse. Multiple-event relocation of the main shock and aftershock epicenters and discontinuous surface ruptures recorded after the earthquake are compatible with northeastward movement on a southwest-dipping thrust, although maximum recorded displacements were less than would have been expected from the observed magnitude. This suggests that most of the slip did not actually reach the Earth's surface