SHATTERED Japan is braced for a fresh quake nightmare - with a mega aftershock likely to hit at any moment.
The alert was issued as millions who survived the tsunami that devastated the hi-tech superpower spent a third day without food, water or electricity - and amid heightening fears of nuclear catastrophe.
Earlier today there was a SECOND blast inside the stricken Fukushima nuclear plant.
Tokyo Electric Power Company said 11 workers were injured and seven were missing after the hydrogen explosion in the No3 reactor.
Japan's world-renowned centre for earthquake prediction said there was a seven-in-ten chance of a tremor with a magnitude of seven or more hitting "within the next three days".
Destruction ... a giant tanker washed ashore near Sendai and train carriages near Fukushima
The heartbreaking warning raised the spectre of another tsunami like the one that was last night feared to have killed up to 20,000.
