A strong earthquake rocked parts of eastern Indonesia on Saturday, causing some residents to flee their homes in panic, but there were no immediate reports of damage or injury, AP reported. The tremblor, with was initially measured at magnitude 6.4, struck 183 kilometers (113 miles) to the west of the coastal city of Jayapura in Papua province, according to the U.S. Geological Survey. «I felt unsteady on my feet and saw people running from their homes,» said Jayapura resident Robert Fanwi. He said the quake did not appear to have caused any major damage in his neighborhood. Agung Saptaji, a local geoscientist, said he had received no reports of damage. Quakes of 6.5 magnitude and above can cause extensive damage depending on depth and other factors. Indonesia, the world's largest archipelago with 17,500 islands, is prone to seismic upheavals because of its location on the so-called Pacific «Ring of Fire,» an arc of volcanoes and fault lines encircling the Pacific Basin. A giant quake off Indonesia's Sumatra island in 2005 spawned the Asian tsunami and killed more than 230,000 people in 11 countries, more than half of them in Indonesia.