Investigators from the Corruption Investigation Office for High-ranking Officials and the National Police Agency walk around a vehicle blocking the path to President Yoon Suk Yeol's residence in Seoul, Wednesday. Yonhap

When thousands of police officers gathered near the heavily fortified residential compound of President Yoon Suk Yeol to execute a court-issued warrant to detain him Wednesday morning, many worried this could turn violent.

However, no serious violence occurred during the joint operation by police and the Corruption Investigation Office for High-ranking Officials (CIO), which mobilized some of the best members they had, including experienced detectives who specialize in violent crimes.

"Unlike the first [botched] attempt to execute the warrant, no official from the Presidential Security Service (PSS) tried to stop us aggressively. No physical clashes occurred," a CIO official told reporters.

Since the launch of an investigation targeting the president over his declaration of martial law early last month, directors of the security service vowed to protect him, saying that they would take necessary action for any attempt to enter the restricted area without approval.

But this time, there was little resistance from presidential security agents, who successfully frustrated the investigation team's first bid to detain Yoon after hours of standoff on Jan. 3.

Before sending the investigators into the facility, police warned through a loudspeaker that anyone trying to hinder their efforts to detain the impeached leader could be apprehended over obstruction of justice charges. Soon afterward, investigators and police officers used ladders to get over barricades of buses that blocked the road at the main gate.

Investigators from the Corruption Investigation Office for High-ranking Officials and the National Police Agency walk inside the residential compound of President Yoon Suk Yeol in Seoul, Wednesday. Newsis

As they were approaching the building where the president was staying, they encountered his attorneys, security agents and lawmakers of the ruling People Power Party, as well as barricades made using vehicles. But no one attempted to stop them by force, although there were some tussles and shouting. By 10:40 a.m., Yoon was in custody.

When the CIO was regrouping for a second attempt to detain Yoon in cooperation with the police, the PSS already began to show signs of division, with many agents expressing concerns that they could be detained on the spot if they blindly followed the orders of their superiors.

"It is true that many in the PSS said they should not stand in the way this time," an official at the security service reportedly said.

Kim Sung-hoon, acting chief of the PSS, and Lee Kwang-woo, head of its bodyguard division, were known as hard-liners who insisted that security agents should use all means necessary to fend off the investigators. It turns out, most others did not agree.

Judges issued warrants to detain the two on charges of obstructing the CIO's previous bid to detain Yoon.

Other than the president, no one was detained on Wednesday, investigators said. They are expected to summon Kim and Lee for questioning after Yoon.