Japan's Nikkei 225 stock index plunged more than 12 per cent on Monday as investors worried that the US economy may be in worse shape than had been expected dumped a wide range of shares, reported Associated Press.

The Japan's Nikkei 225 stock index shed 4,451.28 to 31,458.42. It dropped 5.8 per cent on Friday and has now logged its worst two-day decline ever, dropping 18.2 per cent in the last two trading sessions.