(CNN) Fanta was just 16 when she began having sex with her 30-year-old teacher.

A year later, she found out she was pregnant by him.

The teacher denied he impregnated the student when her father tried to make him accept the pregnancy. Fanta lives in the Sédhiou region of southern Senegal, an area with high teen pregnancy rates.

She abandoned her education as the pregnancy progressed.

Fanta is one of the dozens of girls who told rights group Human Rights Watch (HRW) that they were coerced into having sex with their teachers in Senegal's secondary schools.

"I felt humiliated in front of my classmates," she told HRW.

In a new report titled, "It's Not Normal: Sexual Exploitation, Harassment, and Abuse in Secondary Schools in Senegal," female students -- some as young as 16 years old -- said their teachers lured them to have sex in exchange for better grades, food, mobile phones, and new clothes.

Sixteen-year-old Aïssatou, whom HRW is not identifying by her real name, told the rights group that her teacher lured her to his house.

He threatened to lower grades when she refused his sexual advances.

"One day, he asked me to go to his house. When I went to his house, he offered to give me money and resources. And I told him no. ... He became nasty, (he said) he was not going to give me good grades," she said.

Students who got pregnant by their teachers have had to drop out of school, the advocacy group said.

School-related sexual- and gender-based violence is a serious problem in Senegal, HRW said in the report.

CNN has put in multiple requests for comment to the ministry of education in Senegal but has yet to receive a response.

Government reforms

The Senegalese government has implemented policies intended to protect children against many forms of violence in the country.

In 2013, the government adopted an extensive child protection strategy to tackle cases of abuse and exploitation.

A teacher faces up to a 10-year prison sentence if found guilty of having sexual relations with a student, according to the country's law.

It is also working with international NGOs on programs to prevent teen pregnancies and other forms of abuse in its secondary schools. But sexual violence is still common in Senegal's secondary schools despite laws that forbid it.

Plan International in a 2013 report found that 11% of children in Senegal named a teacher as being responsible for their pregnancy.

HRW children researcher Elin Martinez told CNN that while the government has prosecuted cases of sexual harassment perpetrated by teachers, the majority were not being held accountable.

"There are examples where teachers ask students for sex and harass them via text messages, which government cannot investigate, and schools don't have a confidential system where students can come forward with these allegations," Martinez said.

HRW researchers said it interviewed 160 girls and women, including those who claimed to have been sexually abused by their teachers, 60 parents, and government officials in eight districts of four regions in Senegal.

School principals cover up students' allegations against their staff to protect their reputation and out of fear of losing personnel, the advocacy group alleged in the report.

"Some of the principals just want to fix the cases, they take matters into their hands without necessarily taking it to a higher level," she told CNN.

All hands on deck

Nora Fyles , director of the United Nations Girls' Education Initiative (UNGEI), said the global education community was not surprised by HRW's allegations and the agency is "desperately trying to get on top of it."

"This is not just a human rights issue. It is an education agenda issue, and we are aware of it. We cannot see it continue," Fyles told CNN.

Fyles added that the education ministry in Senegal is working with UNESCO and international partners on training and improved curriculum to address gender violence in schools.

She said that "teachers and their unions should be at the forefront of solutions."

HRW called on the government to prohibit sex between students and their tutors outright.

It wants principals in schools to investigate all sexual assault allegations, and refer cases to police and prosecutors.

"The government wants girls to succeed in education," Martínez said.

"But it needs to end the culture of silence around abuse by teachers, encourage girls to speak out, and send an unequivocal message to all education staff that it will not tolerate sexual violence against students."