SEOUL, SOUTH KOREA: An 80-year-old South Korean man was unconscious and experiencing breathing difficulties after setting himself on fire during a large anti-Japan protest in Seoul, hospital officials said.

The rally, held in front of the Japanese Embassy and attended by hundreds of people, was staged days before the 70th anniversary of the Allied victory in World War II that freed the Korean Peninsula from Japanese colonial rule.

Kim Sun-min, who was among several people who rushed over to help put out the flames, said he didn't notice the man before he set himself ablaze on a flower bed near the rally. Lumps of burnt cotton and a small glass bottle that reeked of gasoline were found at the scene. The rally continued after the man was taken to the hospital.

The man suffered third-degree burns on his face, neck, upper body and arms and was relying on a breathing machine after his lungs deteriorated, according to an official at Seoul's Hallym University Medical Center, who didn't want to be named, citing office rules.

Police had initially said the man appeared to have avoided life-threatening injuries.

His motives weren't immediately clear.

Activists since 1992 have organised weekly protests in front of the Japanese Embassy to demand justice for South Korean women who were forced to work as sex slaves for the Japanese military during the war and the gatherings have been mostly peaceful. The turnout was particularly high on Wednesday as the countries approached the anniversary.

Many South Koreans harbor deep resentment against Japan over its colonial occupation. Hundreds of thousands of Koreans were forced to fight as front-line soldiers, work in slave-labor conditions or serve as prostitutes in brothels operated by the Japanese military during the war.

Such sentiment has strengthened in recent years over what South Koreans feel as Tokyo's attempts to downplay its wartime conduct and also its territorial claims over a set of small islets occupied by South Korea.

Protests sometimes turn violent. Scuffles with police are common and demonstrators have severed their own fingers or hurled excrement at the embassy in the past.