SEOUL, Jan. 8 (UPI) -- A South Korean court ordered Japan to pay compensation to 12 so-called comfort women who were used as sex slaves during World War II in a landmark ruling issued Friday that is likely to inflame tensions between the East Asian neighbors.
In its verdict, which is the first of its kind, Seoul Central District Court ruled that Japan must pay damages of $91,900 to each of the five surviving plaintiffs and the family members of those who have died since the case was originally filed in 2013.
The women were abducted and forced into wartime brothels where they were "exposed to constant violence, torture and sexual assault," the court wrote in its ruling, actions it described as a "crime against humanity."
Japan's foreign ministry issued a statement protesting the ruling later Friday, calling it "absolutely unacceptable" and announcing that it had immediately summoned South Korean Ambassador to Japan Nam Gwang-pyo.
The ministry's statement repeated Japan's long-held contention that all wartime reparations claims were settled by a 1965 bilateral treaty that normalized relations between the two countries.
A further 2015 agreement between then-Japanese Prime Minister Shinzo Abe and the since-impeached South Korean President Park Geun-hye contributed some $8 million to set up a foundation to support the comfort women. The ministry called the step a "final and irreversible solution" between the two governments in its statement.
However, in 2017, South Korean President Moon Jae-in declared that the negotiations had serious flaws and said the agreement "does not resolve the issue over comfort women."
The Seoul court wrote in its decision Friday that the victims' rights to claim damages were not overridden by the state-level agreements.
Japan did not participate in the case and has argued that it has state immunity, a doctrine that says a sovereign state cannot be sued in a foreign court without its consent.
Friday's verdict also rejected that claim.
"[Japan's acts] are a crime against humanity, violating the international norms of enforcement and were committed against the plaintiffs who were Korean citizens on the Korean Peninsula, which was under illegal occupation by the Japanese Empire at the time," the verdict read.
Japan occupied Korea from 1910-1945, a period of colonization that ended after World War II. Some historians estimate that up to 200,000 girls and women, mainly Koreans, were used as sex slaves by Japan in military brothels.
The relationship between Seoul and Tokyo is complicated at best, but ties have been particularly strained since South Korea's Supreme Court ruled in 2018 that two Japanese companies must pay compensation to wartime victims of forced labor.
The ruling sparked a trade war and led to a widespread boycott of Japanese products in South Korea. Seoul also threatened to withdraw from a military intelligence sharing agreement with Tokyo before deciding to remain in the pact in 2019 under pressure from Washington.
Kim Kang-won, the lawyer for the plaintiffs, praised Friday's verdict, saying he felt "very emotional," adding he would review ways to enforce the court's decision, news agency Yonhap reported.
Another ruling in a similar case against Japan involving former comfort women is expected next Wednesday.