The operator of Japan's crippled nuclear power plant says workers discovered a small fire near a reactor building at its tsunami-stricken Fukushima Dai-ichi complex but it was extinguished quickly.
Tokyo Electric Power Co. says the fire at a box that contains batteries in a building near the No. 4 reactor was discovered at about 6:38 a.m. Tuesday morning and was put out seven minutes later.
It wasn't clear whether the fire was related to a magnitude-6.3 earthquake that shook the Tokyo area Tuesday morning. The cause of the fire is being investigated.
The plant was damaged in a massive tsunami that knocked out cooling systems and backup diesel generators on March 11, which led to explosions. Engineers have been able to pump water into several reactors to restore cooling functions.