The benchmark Korea Composite Stock Price Index(KOSPI) closed lower Monday, ending its five-day rally amid mounting uncertainties after the U.S. launched airstrikes on key Iranian nuclear facilities over the weekend.

The KOSPI shaved off seven-point-37 points, or zero-point-24 percent, to close at three-thousand-14-point-47.

The KOSPI shot past three-thousand Friday on investor optimism over President Lee Jae Myung’s new policies, but those gains were muted after the U.S. conducted airstrikes on three key nuclear sites in Iran over the weekend, further aggravating tensions in the Middle East.

Chip and biotech stocks led the market slide, with Samsung Electronics down two-point-52 percent and Samsung Biologics dropping two-point-36 percent.

Battery and heavy machinery shares also retreated, with LG Energy Solution falling three-point-61 percent and Hanwha Aerospace losing two-point-03 percent.

The tech-heavy KOSDAQ lost six-point-74 points, or zero-point-85 percent, to close at 784-point-79.