A magnitude-5.1 earthquake shook eastern Japan (search) on Sunday, swaying tall buildings in the capital Tokyo, the Japanese Meteorological Agency (search) said. There were no immediate reports of damage or injuries and no risk of tsunamis, national broadcaster NHK (search) said.

The moderate quake was centered about 24 miles underground just northeast of the capital in Ibaragi prefecture, the Meteorological Agency said.

Tokyo's metropolitan area is home to some 35 million people, or about a quarter of Japan's population. A quake with an estimated magnitude-8.3 hit Tokyo in 1923, killing 142,000 people. Powerful quakes in 1703, 1782, 1812 and 1855 also caused vast damage in the city.

Japan sits at the juncture of four tectonic plates -- or moving slabs of the earth's outer crust. It is one of the world's most earthquake-prone countries.

A powerful magnitude-7.6 struck the divided Himalayan territory of Kashmir (search) on Oct. 8, killing more than 38,000 people on the Pakistani side and more than 1,300 on the Indian side.