JAKARTA, Indonesia (AP) — A strong undersea earthquake shook western Indonesia on Wednesday, but no injuries were immediately reported.

The U.S. Geological Survey said the magnitude 6.2 quake struck at a depth of 10 kilometers (six miles) and was centered 217 kilometers (135 miles) south-southwest of Bengkulu city in Bengkulu province on the southwestern side of Sumatra island.

No tsunami warning was issued by the Indonesian Meteorology, Climatology and Geophysics Agency and no casualties were immediately reported.

Indonesia, a vast archipelago of 271 million people, is frequently struck by earthquakes, volcanic eruptions and tsunamis because of its location on the “Ring of Fire,” an arc of volcanoes and fault lines in the Pacific Basin.