Police say elderly man phoned an acquaintance to say he planned to self-immolate to express his ‘hostility’ to Japan.

An elderly South Korean man has died hours after setting himself on fire outside the Japanese embassy in Seoul, police said, at a time of worsening ties between the East Asian neighbours.

The 78-year-old man, surnamed Kim, ignited a fire inside his car parked in front of the embassy building early on Friday. He died while being treated at a Seoul hospital, police said.

Kim spoke to an acquaintance on the phone while driving to the Japanese Embassy from his home and said he was “setting fire” because of “his hostility against Japan“, a police officer at Seoul’s Jongno Police Station told the AFP news agency.

Kim’s family told investigators that his father-in-law had been conscripted as a forced labourer when the Korean Peninsula was under Japan’s colonial rule from 1910-45, the police said.

No suicide note was found, and police said they have launched an investigation to determine the exact motive for Kim’s action.

The man’s self-immolation came as Japan’s Foreign Minister Taro Kono publicly admonished South Korea‘s ambassador Nam Gwan-pyo in a deepening dispute over compensation for Korean forced labourers during the Japanese occupation.

Kono summoned Nam on Friday, a day after the passing of a deadline set by Japan for South Korea to accept third-country arbitration on the forced labour dispute.

The issue was thrust to centre stage last year when a South Korean court ordered two Japanese firms – Nippon Steel and Mitsubishi Heavy Industries – to pay compensation to Koreans forced to work for them.

Japan says the whole compensation issue was settled under a 1965 treaty.

Kono said South Korea had to “immediately take corrective measures” over the court ruling.

“What the South Korean government is doing now is equivalent to subverting the post-World War II international order,” he said, adding that it was “extremely rude” of Seoul to suggest Japanese and South Korean firms voluntarily set up a joint compensation fund for forced labour victims.

To Kono’s remarks, Seoul’s foreign ministry insisted Tokyo should “make efforts to heal the pain and wounds” of the Korean victims for the dispute to be “truly resolved”.

The dispute appears to have spilled over into Japan and South Korea’s trade in hi-tech materials used to make memory chips and screens.

Earlier this month, Tokyo announced restrictions on the export of several chemicals to Seoul’s chip-making giants, in a move South Korean officials described as retaliation for the compensation rulings.

Japan denies that, instead citing “inadequate management” of sensitive items exported to South Korea.

Seoul has threatened to take the issue to the World Trade Organisation and also urged Washington to intervene.