A Seoul court has dismissed a damages suit brought on by Korean victims of Japan's wartime sexual slavery and their families, causing a setback in their efforts to hold Tokyo accountable for war crimes.

The Seoul Central District Court on Wednesday dismissed the case filed by 20 victims and their families in 2016, citing sovereign immunity, a legal doctrine that allows a country to be immune from civil suits in foreign courts.

The latest decision stands in stark contrast to a ruling by the same court in January, which had ordered Japan to make reparations of 100 million won each to the first group of 12 victims.

At the time, the court had ruled that sovereign immunity should not apply to "systematic crimes against humanity" and war crimes.