Investment grade bond funds attracted some $2.2 billion, high yield bond funds around $700 million and emerging market debt funds some $1.6 billion, the data showed.

"Bond investors are risk on," BAML's global strategy team, led by Michael Hartnett, said in its weekly flows report. "In contrast, equity investors are risk off," it added, noting outflows from all regions.

The biggest outflows were from Japan, with some $2.3 billion of redemptions. These are the largest outflows since November 2014, according to BAML, which also uses data from U.S.-based fund flows research house EPFR Global.

"Overseas investors continue to lead the retreat from Japan despite the strong support its market is getting from the Bank of Japan's current quantitative easing program," EPFR Global said. It added that the yen's value had cast a shadow over the country's export story as it climbed to a 17-month high versus the dollar this week.

BAML said the outflows coincided with the first underweighting of Japanese stocks since December 2012 in its monthly fund manager survey. It also noted the 7 percent bounce in the Topix index <.TOPX> in the last five days.

European equities racked up $2 billion of outflows, their 10th consecutive weekly outflow, and the longest redemption streak since May 2013. U.S. stocks saw $1.3 billion of outflows.

However, BAML said the equity redemptions were "very modest" so far, in comparison to the jump in cash levels seen in the fund manager survey to 5.4 percent of investors' portfolios.

In total, bond funds attracted some $4.5 billion, with investors favoring higher yielding debt over plain vanilla government and Treasury bonds, which saw $1.1 billion of outflows.

Emerging market debt funds have now attracted inflows for eight weeks straight, whilst high yield bond funds have enjoyed inflows for seven of the past eight weeks.

By Claire Milhench