Seoul, March 3 : South Korean stocks plummeted nearly 5 per cent late Tuesday morning amid escalating concerns over possible economic impacts from the ongoing Middle East conflict.

South Korea's main bourse operator, the Korea Exchange (KRX), issued a sell-side circuit breaker, temporarily halting trading after a sharp drop sparked by market concerns over U.S. airstrikes on Iran.

Selling of the KOSPI 200 Futures index was suspended for five minutes at 12:05 p.m., according to KRX.

The index fell 47.75 points, or 5.09 percent, to 890.05 at that time. It marked the first sell-side circuit breaker since Jan. 6.

A sell-side sidecar is triggered when the KOSPI 200 Futures index drops 5 percent or more for at least one minute.

Opening 1.26 percent lower, the benchmark Korea Composite Stock Price Index (KOSPI) fell 246.98 points, or 3.96 per cent, to 5,997.15 as of 11:20 a.m. in the first trading session following the U.S.-led attacks on Iran, reports Yonhap news agency.

The South Korean financial market closed Monday in observation of the March 1 Independence Movement Day holiday.

Overnight, U.S. stocks closed mixed as investors digested the U.S. air strikes on Iran. The Dow Jones Industrial Average fell 0.15 percent, but the Nasdaq Composite gained 0.36 percent.

In Seoul, major shares led the decline.

Market bellwether Samsung Electronics sank 5.2 percent, and its chipmaking rival SK hynix tumbled 5.66 percent.

Samsung Biologics, leading pharmaceutical firm, lost 3.77 percent, and flag air carrier Korean Air plunged 8.99 percent.

However, S-Oil, an oil refinery firm whose largest shareholder is Saudi Arabia's Aramco, surged 16.45 percent, and defense giant Hanwha Aerospace soared 11.72 percent.

The Korean won was trading at 1,467.3 won against the U.S. dollar as of 11:20 a.m., down 27.6 won from the previous session.

/IANS