SEOUL — A South Korean court on Friday sentenced former President Yoon Suk Yeol to five years in prison on charges that included abuse of power, obstructing justice and falsifying documents following his failed bid to impose martial law in December 2024.

This is the first of the verdicts in four trials linked to his shock martial law decree. Although short-lived, the move triggered nationwide turmoil, sparking protests as MPs rushed to the national assembly to overturn Yoon's decision.

The Seoul Central District Court found Yoon guilty of mobilising the presidential security service to block authorities from executing an arrest warrant to investigate him for his martial law declaration.

In televised proceedings, the 65-year-old former prosecutor was also found guilty of charges that included fabricating official documents and failing to follow the legal process required for martial law, which has to be discussed at a formal cabinet meeting.

"The defendant abused his enormous influence as president to prevent the execution of legitimate warrants through officials from the Security Service, which effectively privatised officials ... loyal to the Republic of Korea for personal safety and personal gain," the lead judge on the three-justice panel said.

Speaking outside the court immediately afterwards, one of Yoon's lawyers, Yoo Jung-hwa, said the former president would appeal. "We express regret that the decision was made in a politicised manner," she said.

Friday's ruling offers clues as to how the rest of Yoon's trials could go.

About 100 supporters of Yoon had gathered outside the courthouse on Friday to watch the livestreamed proceedings projected on a large screen.

Some of them held red banners that read: "Yoon, again! Make Korea great again". Several could be heard yelling at the judge as he delivered the guilty verdicts, while others looked solemn.

Prosecutors had sought a 10-year jail term for the charges in Friday's ruling. Both sides have seven days to appeal.

Yoon denied the charges, arguing that the arrest warrant itself was invalid and that the letter of the law does not require him to consult every member of the cabinet before exercising emergency power.

He had claimed across his trials that investigators had no legal basis to probe and arrest him in the first place. Most of the accusations against him are invalid because there was no procedural lapse when he declared martial law, he argues.

Six months after Yoon's martial law attempt, voters elected opposition leader Lee Jae Myung in a decisive victory .

But Yoon's trials bring the spotlight back to deep divisions in South Korea, where the former president retains strong supporters who see him as a martyr. According to a survey conducted last December, nearly 30% of South Koreans did not believe that Yoon's martial law declaration amounted to an insurrection.

While his martial law attempt brought tens of thousands of protesters onto the streets, it also saw his supporters show up in counter protests, though in smaller numbers. — Agencies