India, April 21 -- A powerful earthquake struck off the northern Japanese coast, and the Japan Meteorological Agency issued a tsunami alert in the region.

The quake, registering a preliminary magnitude of 7.5, occurred off the coast of Sanriku in northern Japan at around 4.53 pm (0753 GMT), at a depth of about 10 kilometres (6 miles) below the sea surface, the agency said.

A tsunami of about 80 centimetres (2.6 feet) was detected at the Kuji port in the Iwate prefecture, and a smaller tsunami of 40 centimetres (1.3 feet) was recorded at another port in the prefecture, the agency said.  The agency urged residents in the region to immediately stay away from the coast or along rivers and take shelter on higher ground. It also cautione...