Network failures and service disruptions occurred in key areas of Yeouido and Gwanghwamun in Seoul on Saturday, as thousands of citizens filled the streets ahead of the impeachment vote for the embattled President Yoon Suk Yeol.

“I could not send any messages on KakaoTalk or Telegram when I reached the front of the National Assembly. My connection was restored when I moved farther away from the Assembly,” a protester said.

Media outlets seeking to livestream the rally in front of the National Assembly also faced difficulties connecting to the internet.

Telecommunications firms said they were closely monitoring the situation and were preparing to ramp up traffic capacity in the areas where large protests are being held, including Yeouido and Gwanghwamun.

“We have already deployed additional mobile base stations to the areas with large crowds, and we have improved traffic capacity. We are reviewing a further addition of mobile base stations in case more people gather in these areas,” an SK Telecom official said.

As large protests were anticipated following the opposition party's impeachment motion against the president, the telecommunications firms boosted their cellular base stations and traffic capacity in advance to handle the surge in network usage in key areas in Seoul.

KT and LG Uplus also ramped up their network systems ahead of time, deploying mobile base stations in addition to their regional cell towers to enhance coverage.

KT said it set up a central situation room at its Gwacheon Network Control Center in the Greater Seoul area, to monitor the overall traffic situation. The company also launched situation rooms in six major cities and carried out inspections of its network facilities in key areas in Seoul including Gwanghwamun, Yongsan and Yeouido.

“We are closely monitoring the situation and plan to increase our base station capacity if necessary. We will take steps to prevent connection disruptions and outages,” an industry official said.

Naver and Kakao, the country's top internet giants, have also ramped up their traffic capacity to prevent the recurrence of service malfunctions in anticipation of an impeachment-related traffic surge.

Naver said it had entered emergency operations and deployed additional personnel to monitor traffic. Kakao also said it secured additional servers to handle the traffic and set up emergency response measures.

Their respective portal sites, Naver and Daum, along with community services, suffered disruptions late Tuesday when Yoon made the sudden martial law declaration. Naver and Kakao said the network outage was caused by a traffic surge.