Dozens of protesters shouted and danced at the gate of a nuclear power plant as it restarted on Sunday. It is the first to go back online since Japan shut down all of its reactors for safety checks following the Fukushima nuclear disaster.

Ohi nuclear plant's reactor No 3 returned to operation despite divided public opinion. Last month, the prime minister, Yoshihiko Noda, ordered the restarts of reactors No 3 and nearby No 4, saying living standards could not be maintained without nuclear energy.

Many citizens are against a return to nuclear power because of safety fears after the Fukushima accident.

The government has been carrying out tests and says the reactors are safe to restart.

All 50 of Japan's working reactors were gradually turned off in the wake of last year's earthquake and tsunami, which sent the Fukushima plant into multiple meltdowns, setting off the worst nuclear disaster since Chernobyl.