A powerful earthquake has struck near the southern Japanese city of Kumamoto, a day after a tremor there killed at least nine people.

The magnitude-7.1 quake at a depth of 10km (6 miles) hit at 01:25 on Saturday (16:25 GMT on Friday). A second - smaller - quake hit later.

A tsunami warning was issued, but has now been lifted.

Japan is regularly hit by earthquakes but stringent building codes mean that they rarely cause significant damage.

Thursday's magnitude-6.2 quake caused shaking at some places as intense as the huge earthquake that hit the country in 2011, Japan's seismology office said.

That quake sparked a huge tsunami and nuclear meltdown at a power plant in Fukushima.

Most of those who died in Thursday's quake were in the town of Mashiki in the Kyushu region in south-western Japan where an apartment building collapsed and many houses were damaged.

More than 40,000 people had initially fled their homes, with many of those closest to the epicentre spending the night outside.