New Delhi, June 27 -- As many as 474 earthquakes have rattled an island chain with many active volcanoes in southern Japan since Saturday, June 21, the national weather agency said on Thursday. While no major damage was reported, the residents of the islands have been asked to remain vigilant.

As of Thursday morning, 474 such earthquakes had been observed around the Tokara island chain, south of Kyushu, the Japan Meteorological Agency (JMA) said.

In a statement, it said, "Seismic activity has increased. As this region has experienced extended periods of earthquake activity in the past, please be vigilant against earthquakes that cause strong shaking."

The strongest of the 474 recorded earthquakes were two magnitude 5.1 tremors. Also Re...