A strong quake jolted the Tokara Islands chain in Kagoshima Prefecture on Thursday, but no tsunami warning was issued and there were no immediate reports of injuries or serious damage.

The magnitude-6.1 quake, which hit at around 11:05 a.m., measured upper 5 on the Japanese shindo seismic intensity scale of 7 on Akuseki Island, the Meteorological Agency said. The focus was at a depth of 14 kilometers, with the epicenter in waters near the Tokara Islands chain.

Municipal authorities said they have confirmed the safety of 64 residents and 12 visiting workers on Akuseki Island, situated more than 300 km from Kagoshima city on the main island of Kyushu.

The small island chain that falls within Kagoshima Prefecture has been hit by more than 240 earthquakes since Saturday — mostly minor shakes measuring 1 or 2 on the shindo scale.

The weather agency called for caution against more quakes of up to upper 5 on the shindo scale. But officials and experts say the quakes are not necessarily cause for alarm as they believe the series of quakes is a localized phenomenon.

The area saw a similar series of mostly minor quakes in April, when 265 temblors ranging from shindo 1 to 4 were observed.

Kyushu Railway Co. suspended Kyushu Shinkansen services for about 15 minutes following Thursday's quake due to a temporary blackout, but it resumed operations soon afterward.