A powerful 7.0-magnitude earthquake off Kyushu early Saturday produced a small tsunami but no major damage, authorities said.

The U.S. Geological Survey said the epicenter of the shallow quake, which struck at 5:51 a.m., was about 160 km (100 miles) from the town of Makurazaki. Its focus was about 10 km under the ocean floor, according to both the USGS and the Meteorological Agency.

The Meteorological Agency issued a tsunami advisory but cancelled it about 90 minutes later.

A tsunami about 30 cm high was observed on Nakanoshima, but no major damage from either the quake or tsunami was reported, and a pair of reactors at the nuclear power plant in nearby Sendai were unaffected, Kyushu Electric Power Co. said.

“There was no abnormality at the No. 1 and the No. 2 reactors following the quake,” said Naoyuki Igawa, a spokesman for Kyushu Electric.

Tetsuro Shinchi, an official with the Kagoshima Prefectural Government, said all appeared normal.

“We have not received any reports of injuries or damage following the earthquake and tsunami advisory,” he said, adding that residents were still being told to be cautious.

“I felt a fairly strong jolt, but I have not seen anything unusual.”

A massive undersea quake that hit in March 2011 sent a tsunami barrelling into Honshu’s northeast coast, killing thousands and swamping the cooling systems at the Fukushima No. 1 nuclear plant, sending three reactors into meltdown. The world’s worst nuclear disaster since Chernobyl has displaced tens of thousands of people.