South Korean President Yoon Suk Yeol on Tuesday declared martial law in an unannounced late night address broadcast live on YTN television.
Yoon said he had no choice but to resort to such a measure in order to safeguard free and constitutional order, saying opposition parties have taken hostage of the parliamentary process to throw the country into a crisis.
"I declare martial law to protect the free Republic of Korea from the threat of North Korean communist forces, to eradicate the despicable pro-North Korean anti-state forces that are plundering the freedom and happiness of our people, and to protect the free constitutional order," Yoon said.
He did not say in the address what specific measures will be taken.
Yoon cited a motion by the country's opposition Democratic Party, which has a majority in parliament, this week to impeach some of the country's top prosecutors and its rejection of a government budget proposal.