2 powerful undersea earthquakes hit north of New Zealand and near western Indonesia

A powerful undersea earthquake has struck north of New Zealand, prompting a tsunami watch in the region.

The U.S. Geological Agency said the magnitude 7.7 quake hit Wednesday evening. It was centered at a depth of 6 miles southeast of the Loyalty Islands, it said. It was not expected to cause significant damage or fatalities on land.

The U.S. Tsunami Warning Center issued tsunami watches for New Zealand, Fiji, Vanuatu and other Pacific islands.

The region is prone to earthquakes because it sits along the Pacific "Ring of Fire," a horseshoe-shaped series of seismic fault lines around the ocean.

Meanwhile, 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 6 miles and was centered 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.