TOKYO, May 29 (Reuters) - Japanese government bond (JGB) yields rose on Wednesday to fresh multi-year highs as investors remained cautious of further tightening by the Bank of Japan (BOJ), with a central bank board member saying it could raise rates if sharp yen falls affect inflation.

The 10-year JGB yield rose 3.5 basis points (bps) to 1.070%, its highest since December 2011.

The two-year JGB yield, which tends to be more sensitive to monetary policy expectations, rose 2 bps to a fresh 15-year high of 0.365%.

The market was paying close attention to the yen as it again inched lower despite bouts of suspected interventions from Tokyo at the end of April and early May.

"Along with putting the market on alert for currency intervention, the weak yen heightens expectations for BOJ policy adjustments," with many investors eyeing July for another hike, Katsutoshi Inadome, a senior strategist at Sumitomo Mitsui Trust Asset Management said.

JGB yields have steadily climbed to their highest in more than a decade in recent weeks, after the BOJ dropped hawkish signals and unexpectedly made cuts to its offer of bond purchase earlier this month.

The cut has led many in the market to suspect the central bank seeks to slow the yen's depreciation and has prompted expectations for a full-fledged tapering of the BOJ's bond purchases at its June meeting.

BOJ board member Seiji Adachi said on Wednesday the central bank may raise interest rates if sharp falls in the yen boost inflation or the public's perception of future prices move more than expected.

JGB yields also got a boost from their U.S. peers, which rose to multi-week highs in overnight trading.

The five-year yield jumped 3 bps to 0.620%, its highest since February 2011.

The 20-year JGB yield leapt 3.5 bps to 1.890%, a level last seen in July 2011.

The 30-year JGB yield was up 4 bps at a 13-year peak of 2.225%.

(Reporting by Brigid Riley; Editing by Mrigank Dhaniwala)