Pupils kill teacher 'for desecrating the Koran'
Oluwatoyin Olusase, a Christian, was attacked after an Islamic religious knowledge exam at the school in the north-eastern state of Gombe.
It was not clear exactly what Ms Olusase had done that angered the students.
Police last night confirmed the killing and said their intervention had stopped the incident from turning into a riot.
"We have received information that a female teacher has been lynched by her students. We are investigating," said Joseph Ibi, the state police commissioner for Gombe.
At least 15,000 people have died in religious, communal and political violence in Nigeria since 1999