The signs are tentative, but a series of recent incidents has the South Korean football world on alert for the worrying signs of growing fan thuggery. Away from the few boisterous derby rivalries between the likes of FC Seoul and Suwon Bluewings, many clashes in South Korea's top division can take on the phizog of the endured, playing out as positively sedate affairs. Staged inside quarter-full monolithic stadiums built for a long since elapsed World Cup, crowd activity is often sapped as on-field play needles toward the taciturn and the number of visiting fans can be scratched in Roman numerals on the back of a postage stamp.

Yet, certain aspects of this anodyne atmosphere are part of an image K-League bosses have been only too happy to cultivate – the appearance of family friendly entertainment apparently key to boosting long underwhelming attendance figures. But this carefully manicured façade is in danger. 

This season, the latest blow came during a clash between Incheon United and Daejeon Citizen where violence erupted on the pitch between the most unlikely of adversaries: Daejeon fans attacked and reportedly “beat up” the home side’s club mascot, leading to fights in the stands between the rival sets of supporters. It capped off a year to forget for Korean football after the 2011 K-League season was almost completely undermined by an apparently deep-rooted match-fixing scandal.

That unsavoury affair saw the K-League Cup scrapped, dozens of players banned for life, and several players and a coach commit suicide. Though not generally noted for widespread fan violence, some observers detect an uptick in incidents in South Korea in recent times. Former South Korea national team boss Huh Jung-moo, who led the Taeguk Warriors to the 2010 World Cup and now the Incheon manager, was scathing in his criticism of those involved in the late March fracas, hinting at a more deep-seated problem in the South Korean fan psyche.

“For the K-League to develop, the fan culture must change first. They should patiently support their team instead of letting a win or a loss of a game determine their emotions so much,” raged Huh. “England is a country that has a lot of these kinds of incidents, but they have almost no stadiums with iron fences. A more fundamental solution is needed. The change in the mindsets of fans is more important."

But Incheon officials intimated that should there be a repeat of the crowd trouble, they will investigate the possibility of installing higher rails to make it more difficult for fans to enter the field of play. Both clubs were fined and fans involved in the incident banned from future matches in the aftermath. It would represent another major dent in the image of the South Korean game if fences were to start appear at stadiums around the country. In recent times, the most high-profile incidents surrounding K-League clubs have come in the shape of anti-Japanese hostilities. Late last year during an Asian Champions League clash between the K-League’s Jeonbuk Motors and the J-League’s Cerezo Osaka,  a section of the Jeonbuk faithful had resorted to the unthinkable by unfurling a banner, written in Japanese, emblazoned with the words: 'Let's celebrate Japan's big earthquake.' The incident sparked outrage. The Japanese, whose country suffered massive loss of life and property after a devastating earthquake and subsequent tsunami earlier in 2011, were deeply insulted. Some point out this sphere in particular could provide the seedbed for further breakouts of fan violence due to the history of animosity felt by Koreans toward Japan after spending 35 years as a colony of the Japanese empire.

Domestically, the most noted conflicts have emerged between capital club Seoul and Suwon, thanks to their long-held geographical rivalry. Seeded in the days when Seoul were known as Anyang Cheetahs, playing out of Anyang, a rival city to Suwon in the province of Gyeonggi, a short drive south of the capital. Today, they are South Korea’s biggest two clubs and both compete within the boundaries of the greater Seoul metropolitan area. According to observers, there have been a number of worrisome encounters between supporters in recent times.

The football authorities made a show of coming down hard on the clubs involved in the Incheon-Daejeon incident, and the police launched an investigation, but both keen followers of the domestic game and club officials want to see the incidents nipped in the bud before a wider culture gets the chance to develop. 

Kim Hyun-cheol, a former sports reporter in Seoul now based in Europe, says the most fertile ground for violent confrontations on the home front is within the confines of this “derby” fixture: "Other than Seoul and Suwon, there are some others such as Ulsan (Tigers) and Pohang (Steelers), Seongnam (Ilhwa Chunma) and Suwon, Daejeon and Suwon, and Pohang and Seongnam," he says. "But they are definitely not as intense as Suwon and Seoul."

The Korean character is often most noted for its tendency toward passionate outburst and a fiery temperament. The most visible manifestations of this as far as outside eyes are concerned come when South Korea’s national legislature makes international headlines because politicians have resorted to violence to block contentious legislation. Alan Green, of the Seoul-based English language newspaper the Korea Times, reckons incidences of football-related thuggery are still sporadic in Korea but that recent evidence demonstrates why Korean football authorities need to be keeping closer counsel.

“I would say that it's still very rare in Korea at domestic level but more likely during international or Asian Champions League games,” he says. “You had a Korean fan hold up a sign mocking the Japanese earthquake and tsunami last year when a Korean side played a Japanese club in the Asian Champions League. Then Korean players were involved in a brawl on the field against a Middle East team. If these incidents continue, it's inevitable that a small element seeking reprisal in the stands will develop. Security is so lax that it could become a major problem if not stamped out fast.”