Shares of exchange-traded funds that buy stocks in South Korea were dropping sharply Tuesday, after the country’s president reportedly declared martial law.

The iShares MSCI South Korea ETF was down more than 6.4%, while the Franklin FTSE South Korea ETF slumped 6% and Matthews Korea Active ETF was down 5.6%, according to FactSet data, at last check.

South Korean President Yoon Suk Yeol on Tuesday declared an “emergency martial law." The president accused the country’s opposition of controlling parliament and sympathizing with North Korea, news reports said.

Samsung Electronics is by far the biggest holding in the iShares MSCI South Korea ETF, at around 22% as of Dec. 2, data on BlackRock’s website shows. Other top holdings of the ETF, which has almost $4 billion of assets under management, include SK Hynix Inc., KB Financial Group Inc. and Hyundai Motor.

U.S. and U.K.-listed shares of South Korean stocks fell sharply, with Coupang, the country's largest online retailer, down more than 5%. Samsung shares fell more than 7%.