TOKYO - A massive earthquake that hit Kyushu Island Sunday temporarily disrupted several electronics companies located in the area. Various reports placed the estimated number of injured close to 700, with at least one person killed.

Although Japan is among the most earthquake-prone areas in the world, Kyushu, known as Silicon Island because of the number of electronics companies there, hasn't been struck in centuries.

The quake measured 7.0 on the Richter scale and has been followed by several aftershocks. A magnitude 7 quake can cause tremendous damage in populated areas, and can trigger tsunamis.

Kyushu Island is home to several electronics manufacturing operations, including plants of Rohm, NEC Electronics and Toshiba. Reports indicate local plants suffered minimal, if any, damage, and are back on-line.

At least 13 aftershocks measuring 4.0 or greater on the Richter scale have been recorded since Sunday.