Pakistan, Jan. 22 -- Japan suspended the restart of the world's largest nuclear power plant on Thursday after an alarm went off during reactor startup procedures. The Kashiwazaki-Kariwa plant in Niigata province had been offline since the 2011 Fukushima disaster. TEPCO, the plant operator, said it does not know when the issue will be resolved.

TEPCO reported that a monitoring system alarm triggered the halt, prompting an investigation of malfunctioning electrical equipment. Control rods were reinserted in a planned manner, keeping the reactor stable. Officials confirmed there was no radioactive impact outside the plant.

Read more: Japan restarts world's largest nuclear plant

The restart, originally scheduled for Tuesday, had already be...