As expected Japanese shares were hammered yesterday in the wake of Friday's quake and tsunami, and the explosions at nuclear reactors at Fukushima on Sunday and yesterday.

Shares fell more than 6%, to be down almost 8% since the quake happened after the 1.7% fall late last Friday afternoon after the quake happened.

The Nikkei ended down 6.2% at 9620.49.

Tokyo Electric Power shares plunged 24% yesterday as more bad news emerged about its stricken Fukushima reactors.

There was an explosion in the Number 3 reactor in the late morning that injured 11 people; then a third reactor, Number 2 at Fukushima Daiichi, began to experience cooling problems and a rise in temperatures.

The combination of the news meant Tepco shares were the worst performer in the Nikkei index yesterday as investors quit the stock in droves.

The market could fall again today following more the latest worrying news about the stability of the reactors at Fukushima.

Tepco is a real concern, it has a reported $US90 billion in debt and only $US30 billion in equity and some analysts wonder if it can survive without Government support.

Yesterday's fall was the biggest since December, 2008 when the GFC was in full swing.

The Bank of Japan on Monday made 21,800 billion yen (or $A265 billion)) available to financial institutions in a bid to stabilise markets yesterday.

It is the largest ever liquidity operation by Japan's central bank which said it would make 15,000 billion yen immediately available and a further 6,800 billion over the next two days in order to deal with an expected rise in demand for funds.

The Bank of Japan attempted to steady nervous markets by flooding the financial system with a