Prime Minister Han Duck-soo on Wednesday ordered South Korea's Cabinet to set up a pan-governmental task force to prevent "fake news" from "manipulating public opinion."

The government, based on an estimate by the state-run media watchdog, the Korea Communications Commission, suspects that two foreign internet users left 20 million reactions cheering for the Chinese soccer team within a few hours on an online forum dedicated to the men's soccer match between South Korea and China in Sunday's quarterfinals at the Asian Games in Hangzhou.

Both Daum and Naver block access from China for certain functions, but the users used IP addresses in the Netherlands and Japan, and activated an algorithm to repeat a set of actions with extremely high frequency, according to officials.

The call came after the ruling party raised concerns over the unusually high number of clicks in support of the Chinese soccer team during the match on Sunday, saying that failing to address such internet trolling activities might make web portals vulnerable to election-interference attempts in the future.

The ruling People Power Party, as well as the presidential office, pointed to anomalies in the number of online fans cheering for the Chinese national team on Korean web portal Daum's public forum, as the internet space is typically dominated by Koreans.

The same day, Lee Jong-bae, a member of the Seoul Metropolitan Council affiliated with the ruling People Power Party, accused unidentified sock puppet accounts on Daum's public forum of interfering with business by causing interruptions in data processing. While filing the criminal complaint with the Seoul Central District Prosecutors' Office at 2 p.m., Lee said any attempt to manipulate public opinion through computer-powered mechanisms with malicious intentions is a criminal act.

The proportion of users who left a reaction in support of China came to 93 percent on the public forum for the match. In the end, the Korean team beat China 2-0.

Kakao Corp., the company which operates Daum, disabled the function Monday afternoon amid snowballing controversy, saying its mechanism allowing users to leave an unlimited amount of reactions without logging in "caused public misunderstanding."

The total number of clicks which sent reactions in favor of China came to roughly 30 million until Monday afternoon.

Web portals like Daum and Naver have often created forums aimed at arousing patriotic feelings during international sporting events. Daum's rival web portal had less than 10 percent of those who clicked in support for the Chinese team.

Both Naver and Daum restricted access to users in China in 2019, but the system could not either block or detect users who employ tools like virtual private networks do circumvent the restrictions.

After a court decision not to detain scandal-ridden opposition leader Rep. Lee Jae-myung despite the National Assambly's consent, conservative politicians are seeking to regain momentum by piling pressure on Daum, as they believe the platform has a large number of users who support the party's political opponents.

"I can't shake off the suspicion that Daum could be serving as a host for manipulating public opinion," said People Power Party Chairman Rep. Kim Gi-hyeon on social media Wednesday. Kim proposed a bill in February to compel online users to disclose their nationalities when leaving a comment on a Korean web portal.

The incident is the latest in a string of political actions propelled by Rep. Park Sung-joong of the ruling party who made his suspicions clear Tuesday that Daum "has long suffered interventions from left-leaning groups and China's foreign propaganda apparatus."

People Power Party spokesperson Kang Min-kuk also claimed Tuesday that the incident is proof that any entity intending to disrupt public opinion "could infiltrate into a Korean web portal to manipulate public opinion through (a similar) scheme."

Also on Tuesday, President Yoon Suk Yeol's spokesperson said, in an apparent endorsement to such political comments, that public concern about the potential manipulation of public opinion exposed through the incident was not unreasonable.

There has been a history of using such methods to influence public opinion around the time of elections in Korea, where online comments or any kind of reactions to online posts were once regarded as a barometer of public opinion.

And from 2011 to 2013, the Defense Ministry's Cyber Operations Command under the conservative Lee Myung-bak administration was revealed to have made over 9,000 political comments online during a period in which there were two national elections, one of which saw the election of conservative candidate Park Geun-hye as president.

In the high-profile "Druking" scandal, named after the nickname of a liberal leaning internet user, a group of ardent supporters of former liberal President Moon Jae-in were found in 2018 to have conspired to manipulate the public opinion in their favor. Prime Minister Han said Wednesday that any events resembling the "Druking" scandal must not be repeated.

The incident was followed by a conspiracy theory which surfaced in 2020, known as "Chinagate." An online comment by an individual claiming to be of Chinese-Korean origin alleged that there was a group of sock puppet accounts who use false online identities and promote their political views in support of Moon. The actual identity of the author has yet to be disclosed to the public, while the conspiracy theory, revealed two months ahead of the 2020 general election when the liberal Democratic Party clinched a landslide victory, was neither identified nor debunked.

Korea is now six months away from a general election, while a by-election next week in a Seoul district could serve as a litmus test for public sentiment.