(CNN) Thirty female activists are expected to cross the North Korean border at the Demilitarized Zone (DMZ) into South Korea on Sunday.

The group of women includes feminist Gloria Steinem and two Nobel Peace laureates, Mairead Maguire from Ireland and Leymah Gbowee of Liberia. The group, called WomenCrossDMZ, says the crossing is intended to draw attention to the need for peace between the Korea neighbors.

But it has already caused plenty of controversy.

The group says women need to be involved in the peace-building process. It calls for reuniting families divided by the Korean War, and replacing the 1953 armistice with a permanent peace treaty, demands similar to those made by the North Korean government.

"I feel this is very much our spiritual and political duty to be part of every peace table," Steinem said at a press conference earlier this week. "It has often been the case that citizenry -- women and men -- can make progress when it is not possible for the officials to be able to meet at that moment in time.

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They initially planned to walk across the border but now it seems they will be bussed across.

Human rights abuses for North Korean women

Human rights activists have criticized the event, saying the women's group is missing major problems faced by North Korean women.

"It is absolutely outrageous that they completely ignore the suffering of the North Korean people, especially North Korean women," said Suzanne Scholte, chairman of the North Korea Freedom Coalition. "If they truly cared, they would cross the China-North Korea border instead, which is actually more dangerous now than the DMZ."

North Korean women who cross into China often become victims of human trafficking, ending up forced to work in the sex industry or sold as brides to rural Chinese men.

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This issue was highlighted in a major U.N. Commission of Inquiry report released last year.

"I felt like an animal in a zoo as many men came to see me, young and old, to see if I would be a suitable bride," Park Ji-hyun, a North Korean defector, told the commission.

The trafficked women remain vulnerable to abuse, rape and violence without recourse because they can't turn to Chinese authorities. China automatically repatriates North Koreans who cross into its country without permission. The penalties for defectors include re-education camps, prison and in worst cases -- death.

Scholte said if the DMZ campaigners are interested in highlighting a critical women's issue, they should be talking about trafficking.

"If they would become Women Cross the China-North Korea border, they could actually help stop the horrific violation of North Korean females," she said.

The reported abuses for North Korean women are not limited to the Chinese border. North Korean defectors have testified of rape and abuse in prison camps by fellow inmates or guards.

Controversy over women's march

Campaign organizer, Christine Ahn has been called a North Korea sympathizer -- an allegation she denies.

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"Basically that is a Cold War, McCarthyist mentality," she told CNN in April. "And that kind of framework has enabled Korea to remain divided. I am pro-peace. I am pro-engagement. I am pro-dialogue. I am pro-human rights."

She says she is for ending "the state of war on the Korean peninsula."

Critics including Human Rights Foundation's Alex Gladstein who accused Ahn of "whitewashing the North Korean regime for more than a decade, always excusing the Kims, saying they aren't so bad, and blaming North Korea's problems on South Korea and the U.S."

In stating the mission for the DMZ walk, the group states: "In North Korea, crippling sanctions against the government make it difficult for ordinary people to access the basics needed for survival." It doesn't criticize the North Korean regime or its leaders, Kim Jong Un.

Gladstein said it was also problematic that the group is not talking to any North Korean women who don't work for the government.

"The reality of North Korean women will be swept under the rug by this. And that's the worst part," he said.

Photos: Photos: Peninsula divided – As part of the terms of the armistice that ended the Korean War in 1953, the opposing armies pulled back their frontline positions to create a 4-km-wide demilitarized zone. CNN cameraman Brad Olson shares his images of the DMZ. Hide Caption 1 of 9 Photos: Neutral venue – When the two Koreas meet for talks, they do so in the Joint Security Area (JSA) in Panmunjun, an abandoned village that straddles the DMZ. Hide Caption 2 of 9 Photos: On edge – Our guide stressed to us that we were in an active war zone and should not surprise the other side with "sudden actions" such as shouting and gesturing. We were also made to stay within a very limited area. Hide Caption 3 of 9 Photos: On guard – One North Korean soldier observes us closely with his binoculars through the icicles. Hide Caption 4 of 9 Photos: Inside the North – We visited a high point overlooking Kijongdong village, which is located about 2 km away on the North Korean side within the DMZ. Hide Caption 5 of 9 Photos: Just for show – The village of Kijongdong is located on the North's side of the DMZ. South Korean troops refer to it as a "Propaganda Village," as they believe it is largely uninhabited and just for show. Hide Caption 6 of 9 Photos: Full mast – A North Korean flag flies over the village of Kijongdong. It must be one of the tallest flagpoles in the world. Hide Caption 7 of 9 Photos: Bridging the divide – The Bridge of No Return is where prisoner exchanges were held at the end of the Korean War. We were warned again not to stray into restricted areas or make any sudden gestures. Pointing is considered a hostile act here. Hide Caption 8 of 9 Photos: Just watching – On the other side of the bridge, we spotted some North Korean soldiers looking back from behind the barbed wire, as well as a farmer herding goats in the field. Hide Caption 9 of 9

Steinem responded to the criticism: "It seems to me that the past no contact has not worked. So we feel it's important that we try reaching out -- friendship, contact, walking, doing with our physical selves what we hope can be done politically."

The North Korean government approved the women's group march -- as required for activities concerning the DMZ -- along with a Pyongyang symposium in early April.

Steinem said the group has been "very careful to be even-handed."

Analysts say a women's group being allowed by Pyongyang to hold this kind of event is at least odd -- but it's not unheard of.

In 2013, a group of bikers from New Zealand crossed the border and in 2014, another group drove through the DMZ.