A magnitude-6.5 earthquake struck southeast of Tokyo on Friday morning, the Japan Meteorological Agency reports.

The U.S. Geological Survey measured the temblor at 6.4 and said it was centered at sea about 150 kilometers (93 miles) southeast of Katsuura.

There were no immediate tsunami warnings.

CNN's team in Tokyo says it felt a mild tremor; there are no immediate reports of damage.

(CNN)