South Korean stocks were down Tuesday as investor sentiment dimmed over a reported showdown between the U.S. and China in the South China Sea. 

The benchmark Korea Composite Stock Price Index(KOSPI) ended the day one-point-25 percent lower after losing 29-point-31 points, the biggest fall in two months. It closed the day at two-thousand-309-point-57.

The tech-heavy KOSDAQ also tumbled, losing 21-point-54 points, or two-point-64 percent. It ended the day at 749-point-99, falling below the 800 line for the first time in a month. 

On the foreign exchange, the local currency weakened seven-point-four won against the dollar, ending the session at one-thousand-119-point-two won.