President Yoon Suk Yeol's declaration of martial law is broadcast on a screen at Seoul Station on Tuesday evening. Yonhap

President Yoon Suk Yeol's abrupt late-night declaration of martial law on Tuesday took even senior aides at the presidential office by surprise, with many reportedly unaware until the announcement was made public.

Citing "anti-state forces" within the opposition, Yoon accused them of obstructing national governance through impeachment motions against senior government officials and a reduced budget bill. It was lifted about six hours after the declaration, leaving the country swamped in chaos overnight.

At around 9:50 p.m. Tuesday, broadcasting networks received a message saying, "There will be an emergency government announcement, please connect to the live broadcast."

Journalists stationed at the presidential office rushed to the briefing room, where such announcements are typically made. However, they were not allowed to go in.

Senior aides, including the presidential chief of staff, were urgently summoned back to the presidential office but arrived unaware of the announcement's content.

Speculation about the briefing's content swirled before the briefing started. Journalists reached out to presidential office officials for clarity, but all inquiries were either declined or met with responses indicating that they, too, were in the dark.

Amid a tumultuous and tense atmosphere, the briefing began behind closed doors at approximately 10:25 p.m., with no prior official notice or explanation.

"This is not only unprecedented in any country in the world, but it has never happened since the founding of our nation," Yoon said during the emergency briefing.

He began by criticizing the opposition-dominated parliament, accusing it of sabotaging national governance through budget cuts and attempts to impeach high-ranking government officials.

Four minutes into the briefing, Yoon abruptly declared martial law, framing it as a measure to rebuild and protect the nation's freedom.

"Dear citizens, I am proclaiming martial law to protect the Republic of Korea from North Korea's communist threats and pro-North, anti-state factions undermining our freedom and constitutional order," he said.

The declaration plunged the nation into chaos for nearly six hours until Yoon lifted martial law, following demands from parliament.

Within an hour of the martial law declaration, a dedicated command was established to oversee all administrative and judicial functions.

Army Chief of Staff Gen. Park An-su was appointed as the leader of the martial law command following Yoon's address. The decree also imposed a sweeping ban on political activities, including protests and operations by political parties.

Armed martial law forces attempt to enter the National Assembly building in Yeouido, Seoul, following President Yoon Suk Yeol's martial law declaration. Yonhap

In response, political efforts to lift martial law continued in the National Assembly.

At around 11 p.m., National Assembly Speaker Woo Won-shik issued an urgent call for lawmakers, stating, "All members of the National Assembly should gather at the plenary hall immediately."

This was in preparation for a parliamentary vote, the only legal means to overturn martial law.

Martial law forces blocking the National Assembly building are surrounded by citizens on the streets of Yeouido, Seoul, early Wednesday after the National Assembly passed a resolution demanding the lifting of martial law declared by President Yoon Suk Yeol. Korea Times photo by Shim Hyun-chul

Access to the National Assembly, however, was tightly restricted immediately after the declaration. The doors were closed, allowing entry only to verified personnel.

Around the same time, armed martial law forces, fully equipped with rifles, forcibly entered the National Assembly building. It was an unprecedented move, marking the first such incident since the 1979 declaration of emergency martial law 45 years ago.

Meanwhile, citizens and YouTubers who had gathered outside the National Assembly clashed with police officers blocking access to the building, adding disorder.

The window of the ruling People Power Party policy chief's office at the National Assembly in Yeouido, Seoul, was found shattered early Wednesday following forced entry by martial law troops. Yonhap

Around 11:40 p.m., three helicopters, believed to be military, flew over the National Assembly, and armed soldiers attempted to storm the main building.

Heavily armed martial law troops clashed with National Assembly staff, who attempted to block their entry by barricading the main gate with desks and chairs outside the hall where lawmakers were set to convene to pass the resolution demanding the lifting of emergency martial law.

Some staff used fire extinguishers in an attempt to stop soldiers from entering the plenary hall.

When access to the main office was blocked, some soldiers took a detour to the offices of the PPP representatives, breaking windows to force their way into the building.

National Assembly staff use fire extinguishers to block troops from entering the main area of the building early Wednesday, following President Yoon Suk Yeol's declaration of martial law. Yonhap

Amid the frenzy, the National Assembly convened and unanimously passed a resolution to lift martial law at around 1 a.m. on Wednesday, with 190 lawmakers in attendance. The vote came approximately two and a half hours after the declaration.

Despite the resolution passing, it took several more hours for Yoon to act. He announced the decision to lift martial law at approximately 4:20 a.m., nearly three and a half hours after the motion was passed.

Tensions continue to escalate as six opposition parties filed an impeachment motion against Yoon on Wednesday, and widespread protests are anticipated across the nation.