The Kwangju uprising of May 1980 - an event analogous to the Tiananmen Square crackdown in Beijing in 1989 - has haunted South Koreans for 27 years. Although art-house directors have tackled the subject in low-budget, independent projects, only now is the tragedy the subject of a mainstream movie in the shape of May 18.

The film stars South Korea's most famous actor, Ahn Sung-gi, as a former commando officer who leads the citizens against the soldiers. Pretty-boy pin-up Lee Jun-ki (who starred as a gay jester in The King and the Clown) is a student protester and Kim Sang-kyung (Memories of Murder) plays his protective elder brother.

Even by the standards of South Korean filmmaking, the melodrama is slapped on thick. Prior to the action, the characters enjoy blissfully innocent and peaceful lives; the ending is pure Titanic.

But these lashings of weepiness may have been a deliberate effort to make the grim subject palatable

to today's soap-opera generation, as the brutality of the crackdown is gorily depicted.

For Kim Sang-kyung, the reason to do the film was to remind young Koreans of the battle for democracy all those years ago. 'I knew a bit about Kwangju when I was in college - now I'm 36 - but people in their 20s know less than I do,' he says.

'I made it as close to the truth as possible,' says director Kim Ji-hoon after a screening for foreign journalists in Seoul last week. 'It's purely based on fact.'

Critics were more equivocal about the film's achievements. 'I don't think the evolution of the battle was accurate, but some of the moods of the time were,' says Don Kirk, an American reporter who covered the crackdown in Kwangju and served as a consultant to the filmmakers on the accuracy of their treatment.

As South Korea this year celebrates 20 years since the achievement of democracy, the film's key events are widely known. South Korean special forces deployed to suppress the anti-government demonstrations in Kwangju on May 18 behaved brutally. Furious citizens looted arsenals for weapons to retaliate. Fighting broke out.

The 'black berets' - as the special forces were known - retreated on May 21, leaving citizen militias in control of Kwangju for a week. On May 27, the regular Korean 20th Infantry Division, which was trained in riot control, retook the city after further fighting.

The authoritarian Chun Do-hwan government, which had seized power in a coup five months earlier and declared martial law earlier in May, painted Kwangju as a communist rebellion.

Today, the tragedy is viewed as the first spark in a series of democratic protests that compelled Chun to give up power in favour of free elections in 1987. Official investigations found that 207 civilians were killed and more than 900 injured. However, some claim the real numbers are much higher.

Perceived US support for Chun, and a belief that Washington agreed to or facilitated the deployment of South Korean troops to Kwangju, sparked the first wave of anti-Americanism in South Korea.

In December 1980, the US Information Service library in Kwangju was burned down by protesters.

'The apparent support for the Chun Do-hwan regime was the starting point of anti-Americanism,' says Peter Bartholomew, a US businessman resident in South Korea since the 1960s. 'It was unpleasant for any Caucasian to be on the streets, especially if there were drunk students around.'

Kim Ji-hoon contacted retired general John Wickham, who commanded US troops in South Korea in 1980, to confirm his film's facts. But controversies over Washington's alleged role, and the high-level machinations inside the South Korean government and armed forces are avoided, as Kim focuses almost entirely on his (fictional) characters in Kwangju city centre. 'It's still unresolved how involved the Americans were,' says Kim. 'I did not emphasise the American role, as this film is for Koreans, not Americans.'

Some locals are already concerned about the passions the film may reignite.

'I don't want this film to give people the wrong impression,' says Lee Tae-ha, a Seoul-based entrepreneur and former commando deployed to Kwangju in 1980. 'Everyone was a victim. Koreans should embrace this event as a growing pain on the road to democracy.'