President Yoon Suk Yeol became the first sitting South Korean leader to be detained for questioning by criminal investigators on Wednesday, striking a deal with massed law enforcement officials and ending a weekslong standoff over his declaration of martial law that thrust the country into a political crisis.
Mr. Yoon’s security guards successfully blocked the investigators from detaining him on Jan. 3, when they made their first attempt to serve a court-issued detention warrant. Since then, the country has been gripped by fears that a violent clash might occur if both sides refused to back down.
But when the investigators returned on Wednesday with far more police officers, some of them carrying ladders to scale barricades, Mr. Yoon’s bodyguards put up no obvious resistance.
Mr. Yoon will now face questioning from officials investigating his declaration of martial law on Dec. 3. The investigators can now question him for 48 hours and then could apply for a separate court warrant to formally arrest him.
In a video message released shortly after his detention, Mr. Yoon said he agreed to subject himself to questioning in order to prevent a “bloody” clash between his bodyguards and the police. But he called the investigation and warrant to detain him illegal.
The opposition-led National Assembly had raced to vote down Mr. Yoon’s martial law decree last month, and has since accused him of committing insurrection by sending armed troops into the Assembly to seize the legislature and to detain his political enemies.
At the same time as the criminal investigation, the country’s Constitutional Court is deliberating whether the Assembly’s vote on Dec. 14 to impeach Mr. Yoon was legitimate and whether he should be formally removed from office.
Police buses started massing before dawn on Wednesday outside the hilltop presidential compound where Mr. Yoon has been holed up since his impeachment. He was the first South Korean leader to place his country under military rule since the country began democratizing in the late 1980s.
Investigators and police officers gathered at the main gate of Mr. Yoon’s residence, carrying ladders to get over barricades of buses that blocked the road. They reached the entrance to Mr. Yoon’s residence, where they held discussions with the president’s security guards and lawyers.
Around 8:30 a.m., Seok Dong-hyeon, a lawyer who serves as Mr. Yoon’s spokesman, posted on Facebook that the president had not yet been arrested and that his legal team was negotiating with investigators over the possibility of Mr. Yoon voluntarily submitting himself for questioning.
The investigators have been braced for a repeat of the standoff that occurred on Jan. 3, when they first visited Mr. Yoon’s residence to serve a detention warrant. Then, they were outnumbered by presidential security agents and had to beat an embarrassing retreat after a standoff that lasted five and a half hours.
On Wednesday morning, with Mr. Yoon’s lawyers, lawmakers from his party and personnel from the presidential security service standing outside the compound gates, it appeared that he and his supporters were gearing up to resist the renewed effort for his detention. Live footage of the street leading up to his compound in the morning showed a tense standoff in below-freezing temperatures, with some shoving and physical struggles at one point.
Since the first attempt to detain Mr. Yoon, his security guards had fortified the compound by deploying more buses and razor wire to block gates and walls. Mr. Yoon has vowed to “fight to the end” to return to office and said he wouldn’t surrender to a court warrant that he considers illegal.
South Korea’s acting president, Deputy Prime Minister Choi Sang-mok, warned government agencies involved in the standoff against violence.
“All the people and the international community are watching this,” he said in a statement. “We cannot tolerate physical violence for any purposes because it will irreparably damage the trust of the people and our international reputation.”
The effort to take in Mr. Yoon and force him to answer to accusations of insurrection is the first time in South Korean history that the authorities have tried to detain a sitting president. The unfolding events have gripped the country, with news and social media channels livestreaming coverage. There are fears of a violent clash if neither side backs down.
A day before, the Constitutional Court began a hearing on whether to unseat Mr. Yoon, who did not show up for the proceedings. His lawyers said he feared the investigators would detain him if he left his presidential compound.
During the last attempt to serve the warrant, the Presidential Security Service, a government agency assigned to protect the president and his family, outnumbered the Corruption Investigation Office for High-ranking Officials, or C.I.O., which sought to detain him with the help of the police. It deployed 200 bodyguards and soldiers to block 100 C.I.O. agents and police officers.
