Four people have been injured in an explosion that occurred at the No. 1 reactor of the quake-hit Fukushima No. 1 nuclear power plant, according to Japan’s Kyodo News.

The operator Tokyo Electric Power Co. said that explosion was heard at 3:36 p.m of March 12 (local time), following large tremors and white smoke were seen at the facility in Fukushima prefecture, 250 km to the northeast of Tokyo .

Fukushima No. 1 is one of the nuclear power plants being seriously affected by the 8.9 magnitude quake that hit northeastern Japan on March 11. The explosion took place after the Japanese Nuclear Energy Safety Organisation had ordered the plant to discharge radioactive waste to protect the reactor.

The authorities issued an emergency situation to all the five reactors, two in Fukushima No. 1 and three in the Fukushima No. 2 nuclear power plants. The five reactors stopped working after the quake.

All the people living in the nuclear plant area were asked to evacuate./.