Tokyo's benchmark stock index tumbled three percent in morning trade Monday as a sharp jump in the yen dented exporters, with worries about the global economy and Britain's EU vote casting a dark cloud over markets.

The Nikkei 225 slumped 3.03 percent, or 502.86 points, to 16,098.50, extending a global sell-off, while the broader Topix index of all first-section shares was down 2.95 percent, or 39.26 points, to 1,291.46.