TOKYO - A 5.1-MAGNITUDE earthquake rocked Tokyo on Saturday but there were no immediate reports of injuries or damage, the Meteorological Agency said.

The quake struck at 4:49 pm (3.49pm Singapore time )with its epicentre located off the Pacific coast some 170 kilometres northeast of Tokyo, the agency said.

Its focus was about 50 kilometres below the seabed.

The quake was strong enough to briefly shake buildings in Tokyo.

Japan experiences 20 per cent of the world's major earthquakes. A powerful quake in the northern prefecture of Miyagi on June 13 triggered landslides and killed 12 people. -- AFP