South Korean President Yoon Suk Yeol shocked the nation in a televised address, declaring martial law and calling in troops to secure the National Assembly building where parliament sits.

South Korea's Finance Ministry said on Thursday that the government will activate 40 trillion won ($28.35 billion) worth of market stabilization fund, after President Yoon Suk Yeol's lifting of a martial law declaration affected financial markets.

In Oklahoma, martial law has been declared at least 11 times, according to the Brennan Center's list. One of the more notable instances was in 1921 when Adjutant General Charles Barrett issued martial law in response to the Tulsa Race Massacre.