Riot police have blocked South Korean MPs from entering the country’s parliament building in Seoul after President Yoon Suk Yeol declared martial law on Tuesday.

In a surprise televised address to the nation, Yoon Suk-yeol said North Korean threats and “anti-state forces” had forced him to take the draconian measure.

Martial law normally means government by military rule and the suspension of parliament and ordinary law. South Korea’s military has said that all parliamentary activities and parliamentary parties are now banned.

It comes as Yoon’s People Power Party and the main opposition Democratic Party are locked at an impasse over next year’s budget bill.

“Our National Assembly [South Korean parliament] has become a haven for criminals, a den of legislative dictatorship that seeks to paralyse the judicial and administrative systems and overturn our liberal democratic order,” said Mr Yoon.

He went on to call the opposition, which holds a majority in the 300-member parliament, “anti-state forces intent on overthrowing the regime” and said his martial law decision was “inevitable”.