The US dollar traded at 81.38 yen at 0205 GMT as compared with 78.95 in late US trade Thursday, and a euro bought 114.41 yen from 110.67 within the same time period.

The euro traded at $1.4059 against the US dollar from $1.4014 on Thursday.The yen fell following the G7's announcement earlier Friday morning that they would intervene in the currency markets, said Robert Ryan, a foreign exchange strategist for BNP Paribas in Singapore."The G7 economies in the morning said they would do a joint intervention in the FX (foreign exchange) markets," he told AFP.

"They will intervene to sell yen by the dollar, and as they were announcing that the BoJ (Bank of Japan) came in to buy dollar-yen."

The move would release more yen into the foreign exchange market, thereby weakening the currency and relieving Japan's key export industry which had been under threat from higher rates.

The yen had soared since a massive earthquake and tsunami slammed into Japan on Friday, with the currency hitting post World War II peaks against the greenback on Thursday.

The BoJ had earlier Friday also announced a further infusion into Japan's battered money markets, this time injecting three trillion yen ($37 billion) to ensure that financial institutions in disaster hit regions do not run out.

A total of 37 trillion yen has been released by the BoJ into Japan's financial system in a bid to stabilise the shell-shocked economy.