Rep. Kwon Young-se, center, interim leader of the ruling People Power Party (PPP), speaks during an emergency in-house operational strategy meeting at the National Assembly in Seoul, Wednesday, after investigators detained President Yoon Suk Yeol for questioning over his martial law fiasco. Yonhap

The political divide between rival parties is deepening further after investigators detained President Yoon Suk Yeol on Wednesday for questioning over his martial law fiasco, according to political watchers and party officials.

Yoon was detained 43 days after declaring martial law on Dec. 3, becoming the first sitting president in the nation's history to be taken into custody.

Following Yoon's detention, the ruling People Power Party (PPP) vowed to hold the Corruption Investigation Office for High-ranking Officials (CIO) accountable for what it called the "illegal" execution of the detention warrant, echoing Yoon's assertions of its illegality.

However, the main opposition Democratic Party of Korea (DPK) said the detention is a significant step toward upholding the rule of law. The DPK is now pressing the ruling party to pass a special counsel bill to investigate the treason charges against Yoon.

Rep. Na Kyung-won of the ruling People Power Party, center, speaks at the entrance of the presidential residence in Seoul, Wednesday, as investigators carried out the second execution of the detention warrant for President Yoon Suk Yeol. Yonhap

Interim PPP leader Rep. Kwon Young-se called Yoon's detention a "tragedy," saying the CIO doesn't have the authority to investigate the president. He also criticized the Seoul Western District Court for issuing an "illegal" detention warrant and accused the police of colluding with the DPK.

"We will hold the investigation agency accountable for the execution of illegal warrants until the end," he said.

"The only reason for insisting on the detention of the president was to disgrace him rather than to uncover the truth," Kwon added, saying that Yoon's detention does not justify the illegality of the execution.

PPP floor leader Kweon Seong-dong concurred with the interim leader, saying, "I am ashamed to see that the people and my national dignity have collapsed."

Kweon, calling the warrants "unfair and illegal," criticized the CIO and the police for executing the warrants and accused the judiciary of being complicit in the execution of these warrants.

In addition, the PPP said it plans to file charges against Oh Dong-woon, chief of the CIO, and Woo Jong-soo, head of the police's Special Investigation Unit, for executing the detention warrant for Yoon.

They accused both Oh and Woo of abuse of authority and illegal detention and confinement.

The PPP stated that there were also calls for further actions, such as protest visits to the CIO and holding rallies.

Rep. Park Chan-dae, floor leader of the main opposition Democratic Party of Korea, speaks during a general meeting at the National Assembly in Seoul, Wednesday. Yonhap

The DPK, on the other hand, welcomed the detention.

Its floor leader, Park Chan-dae, expressed relief.

"Although it took a long time, I'm relieved to confirm that public power and justice are still alive in Korea," he said.

Park emphasized that Yoon is a criminal, accusing him not only of violating the Constitution with his martial law declaration but also of obstructing law enforcement.

"The CIO should arrest Yoon and hold him accountable, thoroughly investigating the entire treason situation," he said. "This is the way to restore constitutional order and achieve normalization of the country."

DPK leader Rep. Lee Jae-myung urged the prompt restoration of constitutional order, saying, "We must act swiftly to restore constitutional order and prioritize the people's livelihoods and the economy."

National Assembly Speaker Woo Won-shik also weighed in and said, "I am glad that law enforcement was carried out without conflict, as we had concerned."

Woo added, "With the chaotic situation now behind us, we must focus on stabilizing state affairs and restoring the people's livelihoods."

Woo expressed that he intends to expedite the passage of special counsel laws, which are still under discussion between the ruling and opposition parties.