A blast caused by the build-up of hydrogen hit the 4th reactor of the quake-hit Fukushima nuclear power plant in Japan on Tuesday, Kyodo news agency reported.
Japan's Prime Minister Naoto Kan said earlier that the fire at the 4th reactor resulted in the leak of highly concentrated radiation and urged all people residing within the 20-km (13 miles) distance from the reactor to immediately leave the zone.
TOKYO, March 15 (RIA Novosti)
