BMW's South Korean unit reportedly has apologised over a spate of engine fires, estimated by the country's transport ministry at 27 from January to July, that has prompted a government probe and a major backlash from consumers.

Acording to Reuters, BMW said it would launch a recall of 106,000 diesel vehicles, including the 520d, starting from 20 August, citing defects in the exhaust gas recirculation system as the root cause of the fires.

"For the recent series of fire incidents happened in the country, we sincerely apologise for causing worry and anxiety among people and government authorities," BMW Korea chairman Kim Hyo-joon said at a press conference.

According to Reuters, BMW, the second most popular foreign carmaker in South Korea, said it had learned of the problems in 2016 but identified the root cause of the problem in June this year.

The automaker has announced a "technical campaign" in Europe, followed by recalls in South Korea, citing similar failure rates of the system in both regions.

South Korea's transport ministry told the news agency it had urged BMW executives to cooperate in the ongoing probe, saying they were falling short of submitting related documents. The government launched the probe into the affected models on 16 July.

Last week, transport minister Kim Hyun-mee said the country would investigate the case in a "thorough and transparent manner" and take legal action if needed.

Reuters, citing the Yonhap News Agency, said 13 South Korean BMW vehicle owners had filed a class action lawsuit against the automaker, claiming compensation worth KRW5m (US$4,447.13) each, saying they could not drive their cars out of fear the faulty part could catch fire.