A moderate earthquake struck off western Indonesia early on Sunday. There were no immediate reports of injuries or damage. The 5.7-magnitude quake was centered 150 km southwest of the Indonesian capital Jakarta and 86 km beneath the Sunda Strait, the US Geological Survey said. The temblor, which struck at 5:59 am (0429 IST), said Navita Hendrastuti from Indonesia's meteorological agency.Indonesia, the world's largest archipelago, is prone to seismic upheaval due to its location on the Pacific 'Ring of Fire', an arc of volcanoes and fault lines encircling the Pacific Basin.