The main reactor at Fukushima nuclear plant in northern Japan, 250 kilometres north of Tokyo, exploded this afternoon leading to radiation leaks injuring four people as the authorities told 45,000 residents living within a 10-km radius of the leaking plant to evacuate their homes, Kyodo news agency reported.
"The plant is experiencing a nuclear meltdown," Japanese nuclear scientists confirmed, after Prime Minister Naoto Kan visited the site in a helicopter early today.
Reports said the main building of the plant housing the reactor as well as the outer walls were blown away in the high intensity explosion which occurred at 3.30 pm local time (1200 IST) as the cooling water levels dropped alarmingly through evaporation after the quake had damaged the main plant.
"The loss of cooling water is leading to a meltdown of the reactor," Jiji Press reported.
TV footage showed smoke billowing from the site and reported that the reactor building had been destroyed. the channels and public broadcasters warned nearby residents to turn off air conditioners and not to drink tap water.
People going outside were told to avoid exposing their skins and to cover faces with masks and wet towels.
Kyodo quoting police said that another nuclear plant adjacent to the one which exploded was also malfunctioning with the radiation level reaching almost 1000 times the normal level.
The agency said the damage caused by Friday's catastrophic earthquake in Japan expanded today, with the combined number of people who died or are unaccounted for feared to top 1,600.
The Tokyo fire department send specialised "hyper rescue teams" to the exploded nuclear plants.