SYDNEY — A powerful 7.9-magnitude earthquake struck Papua New Guinea Sunday, shaking homes and sparking a tsunami alert, but there were no immediate reports of casualties or major damage.

The tsunami warning for the Pacific island nation and its neighbors was later canceled.

The tremor struck 40 kilometers (25 miles) west of Panguna on Papua New Guinea’s Bougainville island at a depth of 153 kilometers at 3:30 p.m. local time (0430 GMT), the US Geological Survey (USGS) said.

No reports of damage or injuries have emerged so far, said the PNG Geophysical Observatory in the capital Port Moresby.

“But we know that given such a depth at which the earthquake happened, the chances of any major damage or casualties are not highly likely,” Spokesman Mathew Moihoi told AFP.

“Had there been any major disturbances or damage, we would have known by now,” he said, adding that the area where the quake struck was sparsely populated.

USGS’s preliminary assessment was that light to moderate damage was possible on Bougainville island. The quake was revised down from 8.0-magnitude to 7.9.

The Pacific Tsunami Warning Center said waves of between 0.3 and one meter (1-3 feet) above tide level were possible for some coastal areas of PNG and the neighboring Solomon Islands.

The center issued another statement about an hour later to say that threat had passed.

“Even though it is quite deep at 150 kilometers, because it is such a large earthquake, it will produce shaking on the surface,” Geoscience Australia seismologist Spiro Spiliopoulos told AFP earlier.

Earthquakes are common near Papua New Guinea, which lies on the 4,000-kilometer-long Pacific Australia plate. It forms part of the “Ring of Fire,” a hot spot for seismic activity due to friction between tectonic plates.

In 2013, the Solomon Islands were hit by a devastating tsunami after an 8.0-magnitude quake rattled the region. That tsunami left at least 10 people dead, destroyed hundreds of homes and left thousands of people homeless. — AFP