SEOUL (AFP) - Dozens of South Korean activists clashed with police Tuesday (May 1) as they tried to install a statue to former slave workers in front of one of Tokyo's consulates.

South Korea and Japan are both democracies, market economies and US allies that face North Korea's nuclear threats and China's growing economic might, but ties between them are marred by historical issues.

Many South Koreans bitterly resent Tokyo's brutal 1910-45 colonisation of the Korean peninsula, when millions are known to have been forced into slave work for Japan, and former wartime sex slaves are another hugely emotional issue.

The activists tried to set up a bronze statue of an emaciated man holding a flaming torch in front of the Japanese consulate in the southern city of Busan to commemorate the forced labour victims.

The 2016 installation at the site of a statue of a girl symbolising women forced into sexual slavery for Japanese troops drew angry protests from Tokyo, which for a time withdrew its ambassador.

"The worker's statue next to the girl statue! Move over!" activists chanted during an overnight standoff with hundreds of police.

Dozens of campaigners tried to force their way through police lines in front of the Japanese mission Tuesday, before the protest was broken up.

"We stopped them because they tried to make their way into the area within 100 meters from the consulate office where any public protest is banned," the Yonhap news agency quoted a police official as saying.

Several protesters were wounded, it added.

The labourer statue would be the first of its kind.

A statue to the wartime sex slaves - so-called "comfort women" - was installed in front of the Japanese embassy in Seoul in 2011, and several more have since been put up in South Korea and abroad, including the US, earning Tokyo's ire.

Many slave workers are believed to have perished while working at factories of Japanese firms including Mitsubishi, with some survivors seeking damages in court in the South or Japan.