A strong earthquake, measuring 6.3 on thwe Richter scale rattled Japan's southern Bonin Islands on Thursday morning, a day after a quake of the 7.4 magnitude jolted the region, the USA Geological Survey (USGS) reported.

A tsunami alert was issued. There are still no data on possible victims and no immediate reports of damage from the quake, which struck the area about 145 kilometers southeast of the Bonin Islands, and 1,050 kilometers southeast of Tokyo, the USGS noted.

The quake was some 10 kilometers deep, the AP Agency reported.

Japan is one of the most earthquake-prone countries in the world. In 1995, a quake of the 7.2 magnitude on the Richter scale hit the port city of Kobe and killed 6,400 people.