At least six children were killed when gunmen raided a school in Koumba, southwest Cameroon on Saturday.
Fransisca International Bi-lingual Academy was the victim of the attack.
TV pictures showed a blood stained floor in a room littered with classroom furniture.
An eyewitness, a student at the school - told africanews that he had gunshots before running to hide.
"We were having the French language lesson when we heard gunshots. The teacher was the first to escape and I heard people shouting. When I came back to check, I saw dead bodies in the primary [school] section," said the student whose identity we're keeping for his own safety.
Schools in Cameroon's English-speaking regions reopned two weeks after a lengthy disruption by armed violence and the pandemic - with government promising to give protection to education institutions.
Civilian installations as well as military ones have been targeted in Cameroon's conflict. Rights groups have accused government forces and militia fighters of committing atrocities.
No group claimed responsibility for the attack but authorities put the blame on Ambazonia rebels, a loose militia fighting for the independence of northwest and south Cameroon.
"... I ask the people to stand up to fight these terrorists today in Kumba, we must put an end to this; our children must go to school, they must not be targets because they demand their education," said Ali Aonougu, the administrative head of Koumba sub-division.
Hundreds have been killed in the violence which broke out in 2017 and tens of thousands have been displaced.