A strong earthquake has struck off the southern coast of Java, Indonesia's main island, but there are no immediate reports of damage or casualties.

The U.S. Geological Survey said the magnitude-6 quake struck Wednesday evening and was located 35.4 kilometers (22 miles) under the seabed. It was centered 68 kilometers (42 miles) south-southwest of Bunisari, a village in Cianjur district in West Java province.

The Indonesia Meteorology and Geophysics Agency said the quake had no potential of triggering a tsunami.

Indonesia is prone to earthquakes due to its location on the Pacific "Ring of Fire," an arc of volcanoes and fault lines in the Pacific Basin. A massive earthquake off Sumatra island in 2004 triggered a tsunami that killed 230,000 people in a dozen countries.