After Yoon Suk Yeol became the first sitting South Korean leader to be detained, on charges of insurrection over his failed martial law bid, right-wing groups repeatedly shared a manipulated image they claimed showed US President Donald Trump watching news about Yoon's arrest.

China will make every effort to rescue Chinese nationals who fell foul of scam operations luring them to countries including Myanmar, the public security ministry said late on Wednesday.

Judges at South Korea's Constitutional Court get underway with a trial this week that could remove the country's president from office. Yoon Suk Yeol sent the nation into a democratic crisis six weeks ago when he declared martial law.