A strong earthquake measuring 6.6 on the Richter scale struck off the east coast of Taiwan early Monday (20 April), setting off tsunami alerts in Japan.

The epicentre of the earthquake was located between Okinawa in Japan and Taiwan, about 75 km from Taiwan's eastern coast at a depth of approximately 29 km, according to the US Geological Survey.

Witnesses reported buildings shaking in Taipei, but no immediate damage or injuries were reported.

Japanese authorities have since lifted the tsunami warning for islands in Japan's far south, with Japanese national broadcaster NHK reporting that the tsunami had already arrived at remote Yonaguni, although no details on the extent of the waves were immediately available.

Japan sits at the meeting point of four of the earth's tectonic plates and records more than 20% of the planet's most powerful earthquakes every year.