The South Asian Women's Centre says the Canadian government must step in to ensure the illegal kidnappings stop.
Their calls come after Zaiba Zaiba told police she believes her ex-husband took her young son and daughter to live with him in the Middle East.
"The last time I spoke with my children was July 21, and my daughter was crying and she misses me a lot," said Zaiba, who has full custody of the kids.
The woman's ex-husband took their four-year-old daughter Hosna and seven-year-old son Mateen to Norway in June. But under Zaiba's notarized consent, he wasn't allowed to take them anywhere else and was supposed to bring them back a month later.
Concerns 'particularly for the little girl'
When she received a call from her ex-husband just a few weeks ago, informing her that the children were with him in Afghanistan, she broke down.
It's a case the South Asian Women's Centre has seen before.
"Definitely there would be concerns, particularly for the little girl, how she would be raised," said the oragnization's executive director, Kripa Sekhar. "She would probably be raised in a very, very strict upbringing. She would not have the same freedoms that she's had here."
A major hurdle in Zaiba's case is that if her children are in another country, they would be subject to that country's laws.
The Canadian government could step in and put pressure on the government of Afghanistan to return the children, according to advocates.
"If they can put some sort of pressure on the government of Afghanistan to do everything possible to bring these children back, I think there is some glimmer of hope," Sekhar said.
Zaiba has pleaded with foreign affairs and police for help. Foreign affairs says it's providing consular assistance.