Why chilling statues of women have appeared in buses in South Korea

If you happen to hop on a bus in South Korea, you might just come across one of these female statues.

The statues are meant to pay tribute to "comfort women" — women in occupied countries who were forced to work in Japanese military brothels, during World War II.

SEE ALSO: Japan's prime minister stops short of apology for WWII actions

They were installed in five buses across Seoul, to commemorate international "comfort women" day, which fell on Monday.

See photos of the statues:

South Korea is still home to 37 comfort women, most of whom are in their 80s.

But why is this a big deal?

According to South Korean activists, there were an estimated 200,000 women forced to work as sex slaves for Japanese soldiers.

A large proportion of the wartime atrocities are believed to have happened in Korea, with others in countries like China, Taiwan and the Philippines.

But Japan had for years denied the existence of comfort women, saying that the women were sex workers, and were not forced to provide their services.

It was not until 2015 that Tokyo issued a formal apology and agreed to pay $8.3 million (1 billion yen) to victims in South Korea.

However, some Koreans still find the apology insufficient, saying the agreement was reached without consultation with the victims — and many are still angry.

Who is behind the statues?

The plastic statues were initiated by the president of a Seoul-based transportation company, Lim Jin Wook, who says the government was not involved in the installation.

But Seoul has clearly shown its support for the project, which will run until the end of September.

The city's mayor, Park Won Soon, rode on one of the buses, saying it was an "opportunity to pay tribute to the victims."

One of the stops includes the Japanese embassy in Seoul, and the bus will play a traditional Korean folk song, "Arirang," as it passes.

It will also pass by popular Japanese tourist destinations in Seoul.

According to Lim, he does not want to make Japanese people "feel uncomfortable", but does not want the issue to be forgotten.

But this is not the first time statues of comfort women have been installed in Korea.

A 1.5m tall statue, showing a comfort woman, was earlier last year installed by activists outside the Japanese embassy in the South Korean city of Busan.

Japan called for its removal — and when South Korea refused, Japan recalled some of its diplomats.

The statue was initially removed but was later reinstalled after public protest.