Staff clean up shattered and scattered glass caused by the earthquake at JR Miyazaki Airport Station, in Miyazaki, in south-western Japan. (Kyodo News via AP)
In short:
A magnitude-6.6 earthquake struck off the coast of Kyushu, Japan, at a depth of 36 kilometres.
The powerful tremors caused alarm, but no immediate damage or casualties have been reported.
What's next?
Authorities are monitoring for aftershocks and assessing the region for any delayed impacts or structural damage.
Southern Japan has been hit by a strong earthquake that authorities said did not warrant the kind of megaquake warning that was triggered for the first time last year.
A quake with a preliminary magnitude of 6.9 struck the Kyushu region at 9:19pm local time on Monday, the Japan Meteorological Agency said.
The earthquake was later revised to 6.6 magnitude.
After an investigation, the JMA said the quake did not warrant special measures related to seismic activity in the Nankai Trough.
The Nankai Trough, where the Philippine Sea Plate is slipping under the Eurasia Plate at the bottom of the sea off the south-west coast of Japan, produces massive earthquakes about every 100-150 years.
Japan is frequently hit by earthquakes due to its location along the Ring of Fire, an arc of volcanoes and fault lines in the Pacific Basin.
Experts at the meteorological agency met late Monday to gauge how the latest temblor may be related to the Nankai Trough quakes, but decided not to take any extraordinary measures for the time being.
A Nankai Trough quake off Shikoku in 1946 killed more than 1,300 people.
The area was hit by a magnitude-7.1 quake in August last year.
Strong quakes nearby are seen as a potential indication that a megaquake could be more likely.Â
The tragedy of Japan's 2011 tsunami still haunts many
Photo shows A little Japanese girl in an orange hat smiling broadly while holding a bunch of purple and white flowers
The JMA in August issued a week-long advisory for a "relatively higher chance" of a megaquake as powerful as magnitude 9 after a magnitude-7.1 quake hit the country's south-west.
After Monday's quake, tsunami advisories for waves of a maximum height of one metre were issued for the southern prefectures of Miyazaki and Kochi.
A 20-centimetre tsunami was later recorded reaching Miyazaki city, public broadcaster NHK reported.
All tsunami advisories were lifted around noon.
There were no abnormalities reported at the Ikata Nuclear Power Plant in western Japan or the Sendai Nuclear Power Plant in Kagoshima prefecture, NHK said, referring to the two plants nearest to where the quake occurred.
Reuters/AP