Japanese nuclear inspectors say they have discovered a small, new radiation leak at a nuclear power plant damaged by a strong earthquake earlier this week.

Officials said Thursday inspectors have discovered that radioactive materials leaked from an exhaust pipe at the Kashiwazaki-Kariwa plant after it was hit by an earthquake Monday.

Officials from the Tokyo Electric Power Company, which runs the plant, had earlier admitted that radioactive water leaked into the Sea of Japan and that barrels containing radioactive material had fallen open during the quake. Officials initially under-reported the level of radiation in the water.

Officials insist none of the contamination is harmful to the environment or public health, but the incidents have raised concern about the safety of Japan's nuclear power plants.

The 6.8 magnitude earthquake killed at least 10 people and injured more than a thousand in Kashiwazaki prefecture.

Some information for this report was provided by AFP, AP and Reuters.