A heightened sense of alarm over the yen's surge to record highs prompted Bank of Japan board members to ease monetary policy in 2011 amid a nascent recovery from the shock caused by the massive earthquake, tsunami and nuclear crisis in the northeast of the country that year, the BOJ's minutes showed Monday.

The minutes of policy-setting meetings between July and December in 2011 reveal the BOJ's concern regarding the yen's persistent strength, which was threatening to hurt corporate sentiment, prod manufacturers to shift production overseas and delay the nation's exit from deflation.

During that time, the government scrambled to arrest the yen's appreciation by repeatedly stepping into the currency market, as European sovereign debt woes were pushing market players to seek the Japanese currency as a relatively safe asset.