A court in Seoul has extended the prison term of South Korean President Yoon Suk Yeol for failing to impose martial law in the country last month.

Citing concerns that Yoon could destroy evidence if released, a judge on Sunday issued a warrant allowing investigators to keep the suspended president in custody for up to 20 days.

The 64-year-old was arrested on Wednesday after a weeks-long standoff between investigators and his presidential security team.

The president’s supporters stormed the court after he was detained for a long time, allegedly breaking windows and doors during the incident that Yoon and the president of the country condemned.

The document — and Yoon’s refusal to comply with investigators — is the latest in a series of high-profile incidents that have rocked South Korea’s political crisis.

The document was issued around 03:00 local time (18:00 GMT Saturday).

The ousted president is being investigated by the corruption investigation office of the chief executive (CIO) on charges of treason over the failed 3 December law that caused chaos in the country.

He has been impeached by parliament and suspended – but will be removed from office unless the country’s constitutional court upholds his removal.

Investigators now have 20 days — including the four days Yoon already spent in jail after his arrest — to file charges against the president.

After his detention, Yoon’s lawyer, Yun Gap-geun, told Yonhap News Agency that the president would refuse to be questioned by the CIO.

Pro-Yoon supporters gathered outside the courthouse in anticipation of the verdict, and many entered the building after the judges granted overtime.

Journalists who were at the scene said they saw many people arrested by the police following the incident.

President Choi Sang-mok expressed his “strong regret” for the violence, which is “unthinkable in a democratic society”, adding that the government will increase security in the event of future attacks.

Choi recently stepped into the top job after the South Korean parliament voted against the former President, Han Duck-sooon Yoon’s offensive claims.

Yoon was “surprised” by the courtroom scene, his lawyer said, and called on his supporters to express their views peacefully, according to local media.

The incident is the latest step in an attempt by Yoon’s supporters to thwart charges against the president.

On the night of his arrest, hundreds of pro-Yoon demonstrations he camped outside the presidential palace and clashed with the police trying to arrest him.

A similar incident occurred during an earlier arrest attempt on January 3, where Angry supporters of Yoon hoping to prevent the arrest gathered outside the presidential palace.

South Korean police were forced to abandon their first arrest attempt after the presidential security team blocked the entrance to Yoon’s house.

People’s opinions are divided after Yoon’s shocking declaration of martial law last monthwhich he said was caused by “anti-state forces” in the South Korean parliament, while referring to North Korea.

But some have seen this as the cause of the political chaos that followed their opposition party’s victory in April, as well. Yoon’s unhappiness because of Shikulu’s divorce.

Thousands of people have taken to the streets to demonstrate against the ousted president in the weeks since he tried to impose martial law.