SEOUL (REUTERS) - This month three South Korean companies and the Seoul police have had to pull advertisements and other content after men's rights groups claimed that "small penis" symbols were used, insulting men.

The offending images? Hands with the thumbs and the index fingers pinching towards each other illustrating the reaching out for an object.

But the gesture is also often used to indicate something small in size and in South Korea, it is associated with a strident, albeit now defunct, feminist group that used the image in its logo.

Exacerbating the problem, one advertisement and a menu involved were also advertising sausages.

Following its advertisement, South Korea's largest convenience store chain, GS25, saw a handful of members from the men's group Man on Solidarity protest outside the firm's headquarters. The group's YouTube channel, which posts videos of its protests, has gained more than 200,000 subscribers in just two months.

GS25 withdrew its advertisement and fried chicken chain Genesis BBQ pulled its menu, issuing apologies and stating they had no intention to demean men.

Kakao Bank has apologised for a hand drawn similarly in one of its ads and the Seoul Metropolitan police also removed a hand from a road traffic advertisement saying it wanted to avoid any misunderstanding.

The controversy is the latest flare-up in long-running tension over gender rights in South Korea that has pitted men and women's groups against one another, and also resulted in police looking into whether female comedian Park Na-rae broke any laws with a ribald joke made in March.

The joke on a YouTube video involving a Stretch Armstrong action figure whose arms were brought near his genital area resulted in a storm of complaints that a similar joke by a male comedian would never have been acceptable.

Ms Park, 35, and her agency JDB Entertainment issued statements apologising and her YouTube channel was scrapped.

Police are obligated to look into the matter after a complaint was filed on a website set up to address citizens' grievances, though it remains unclear if charges will be filed.

Ms Park and her agency did not respond to Reuters requests for comment on the potential police action.

Ms Kim Garo, director of the women's policy division at the Ministry of Gender Equality and Family, said while the problems of misogyny and misandry were not new in South Korea, the recent targeting of companies and individuals was.

She added that it was difficult for the government to interfere when protests took the form of consumer action but it would continue with outreach programmes that invited young men and women to discuss issues such as gender equality and jobs.

When President Moon Jae-in came to power in 2017, he pledged to be a president for gender equality, vowing to do more to fix disadvantages for women.

South Korea has one of the largest wage gaps of any Organisation for Economic Cooperation and Development (OECD) country and low political representation for women who hold just 19 per cent of parliamentary seats.

Since Mr Moon took office, women have seen some improvement in wages and are also eligible for bigger government subsidies than men when starting a new business.

Political scientists say, however, many young men now feel their own needs and rights are not being sufficiently acknowledged, adding to widespread discontent over the lack of job opportunities for young people.

"Anti-feminist sentiment is strong among men in their 20s and early 30s, as well as the generation that is becoming adults," said Mr Jeong Han-wool, a senior fellow at Hankook Research Company. Research for a 2019 book he co-authored found 58.6 per cent of Korean men in their 20s said they strongly opposed feminism.

That complicates the outlook for the ruling Democratic Party as it seeks re-election next year when Mr Moon's single five-year term ends.

The party has also lost support among women after multiple sexual abuse scandals involving politicians, contributing to crushing defeats in recent mayoral elections in Seoul and the port of Busan.

Mr Park Jun-young, a 27-year old engineering graduate school student, is among those who think men are now at a disadvantage.

"Feminism in South Korea started with gender equality, allowing women the same access and to break the glass ceiling, but it's turned into something where nowadays young men - who aren't better off than women the same age - have become a target of criticism," he said.