A series of strong earthquakes struck Japan today, rattling plenty of nerves in a country still reeling from the magnitude 9.0 earthquake in March. There have been no immediate reports of damages or injuries from the latest quakes. Tsunami warnings have not been issued.

A  magnitude 6.1 quake struck the northernmost island of Hokkaido at 7:25 p.m. local time, 465 miles northeast of Tokyo. The tremor hit 26 miles beneath the surface, and temporarily left nearly 4,000 homes in the dark, according to the Hokkaido Electric Power Company.

The Hokkaido quake struck less than 24-hours after another strong tremor rattled Japan’s northeast coast. Strong shaking from the magnitude 6.0 quake near the Fukushima Dai-ichi Nuclear Power Plant, was felt more than 150 miles south in Tokyo.

Japan sits on an arc of earthquake and volcanic zones around the Pacific rim, where 90 percent of the world’s earthquakes occur.

The country’s largest earthquake in history left more than 20,000 people dead or missing nearly eight months ago, and triggered the world nuclear crises since the Chernobyl disaster.