Japanese equities opened lower in early trading, tracking overnight losses on Wall Street.
The Nikkei index fell by 1.4% to 66,287.24 points.
Commenting on the market move, Ray Attrill, Head of FX Strategy at National Australia Bank, noted that developments such as "the two-way military action escalation between Iran and the U.S. on Sunday and Monday" meant that "risk assets have had a very poor start to the week."
Among the worst-performing constituents of the Japanese benchmark index, Yaskawa Electric Corp. shares fell by 8.8%, Fujikura Ltd. dropped 6.4%, and Kokusai Electric Corp. declined 6.4%.