At least 70 teachers and over 100 students have been killed in attacks on schools in northeastern Nigeria by the Islamist group Boko Haram in the past 18 months, Amnesty International said in a report on Friday.
Islamist group Boko Haram, which means, "Western education is forbidden," wants to impose Islamic law in northern Nigeria and is considered the biggest threat to security in Africa's top oil exporter.
More than 100 schools have been burned down or forced to close and more than 1,000 teachers have been forced to flee from areas in the north since 2012, the report said.
Teachers told Amnesty International how Boko Haram had targeted them.
"Two members of the group came to my house in the middle of the night, with a machete and a gun. They told me to either stop teaching English and start teaching Arabic or close the school," said a community schoolteacher in north-eastern Borno state, according to the report. "I told them I can't. I don't know how to teach Arabic. They said if I don't, they'll kill me and my entire family."
Another former teacher from Borno who is now hiding in Kaduna, in north-central Nigeria, said: "At least 80 percent of the pupils in my school were taken away by their parents ... In June 2013, Boko Haram warned students not to go to the schools to take the National Examinations Council exams in Bama town. The number of candidates who took the exams reduced drastically."
Last week, gunmen killed at least 40 students who were sleeping in their dorms in one of the worst attacks on a college in Yobe state in northern Nigeria.
Amnesty International urged Boko Haram and the Nigerian government to take immediate action to stop the violence.
"Attacks against schoolchildren, teachers and school buildings demonstrate an absolute disregard for the right to life and the right to education," the report said.
"Amnesty International urges Boko Haram and any affiliate armed groups or individuals in northern Nigeria to immediately stop all attacks on schools, teachers and pupils," it added.
The rights group also called on Nigerian authorities to provide better protection for schools and ensure attacks are properly investigated and suspects brought to justice in a fair trial without recourse to the death penalty.
Nigerian President Goodluck Jonathan declared a state of emergency in three north-eastern states on May 14, ordering in more troops to try to stem an increasingly violent Islamist insurgency.
The Nigerian security forces have also come under fire from rights groups for human rights abuses in northern Nigeria.
Thousands have fled to neighbouring Cameroon, Niger and Chad to escape the conflict between Islamist and government forces.