A 5.5-magnitude earthquake struck east of Taiwan today, the central weather bureau said, but there were no immediate reports of casualties or damage.

The undersea tremor hit at 11.44 am (0344 GMT), 77km southeast of eastern Ilan county at a depth of 11 kilometres, the bureau said.

Taiwan, which lies near the junction of two tectonic plates, is regularly shaken by earthquakes.

A 7.6-magnitude quake killed about 2400 people in September 1999.