TOKYO - Japan's prime minister was furious with executives at a power company at the center of the nuclear crisis for taking so long to inform his office about a blast at its stricken reactor complex, demanding: "What the hell is going on?"

Kyodo news agency reported that Naoto Kan also ordered Tokyo Electric Power Co (TEPCO) on Tuesday not to pull employees out of the Fukushima plant, which was badly damaged by last week's earthquake and has been leaking radiation.

"The TV reported an explosion. But nothing was said to the premier's office for about an hour," a Kyodo reporter quoted the prime minister telling power company executives.