An NGO that focuses on women's rights has urged authorities to look into allegations that several colleges have lowered their minimum entrance-exam scores only for boys.

In a letter to the Ministry of Education this month, Beijing Zhongze Women's Legal Counseling and Service Center argues that the practice allows schools to discriminate against female candidates.

"Many colleges, including prestigious ones, have set different admission grades based on gender without reasonable explanations," said lawyer Lu Xiaoquan, who was in charge of drafting the NGO's letter.