South Korea's financial watchdog called on securities firms Thursday to draw up contingency plans as market volatility is likely to increase amid martial law-related political turmoil.

The local financial markets were roiled on Wednesday by President Yoon Suk Yeol's declaration of emergency martial law late Tuesday, which was lifted hours later after a parliamentary vote to block the decree.

Earlier in the day, the opposition-controlled National Assembly introduced a motion to impeach Yoon over the botched attempt to impose martial law.

The benchmark Korea Composite Stock Price Index fell 10.64 points, or 0.43 percent, to 2,453.36 in the first 15 minutes of trading, following a 1.44 percent dip the previous day.

"The local stock, currency markets have shown signs of stabilizing yesterday, but market volatility is feared to increase depending on the degree of political uncertainties," Hahm Yong-il, senior deputy governor of the Financial Supervisory Service, said in a meeting with heads of local securities firms.

He urged securities firms to draw up contingency plans for possible scenarios and reduce any possible fallout from the political chaos. (Yonhap)