A woman put her grandson up for sale on a street in Wuhan, Hubei province, on Wednesday, to raise money to save her sick son, who is also the the little boy's father, according to cnhubei.com.

Along with a little girl, who was no more than 4 years old, the woman kneeled near a food market in Xinzhou district and kowtowed to passersby on Wednesday morning, a man surnamed Tong said.

A poster in front of her revealed that she is Liu Xiaoying, 57, and that her 30-year-old son was diagnosed with acute leukemia earlier this year. The poor family can't afford the 300,000-yuan fee for his bone-marrow transplant, according to photos provided by Tong.

"I'd like to trade my 8-year-old grandson, who's in primary school, for 300,000 yuan ($47,700) to save my son," the poster read.

Police stopped the woman after being notified.

The woman's son He Dusai and his wife said they didn't know their son was "for sale."

Liu's husband told a reporter that they knew it was wrong to sell their grandson, "but we have no other means. We just hope some kind-hearted people will help save our son."

"Human trafficking is illegal, and it's unfair to the innocent child," Tong said.