The European Union on Sunday condemned the "horrific murder by terrorists" of dozens of people, mostly students, in an attack on a secondary school in Nigeria blamed on Islamist insurgent group Boko Haram.
"I condemn in the strongest possible terms the horrific murder by terrorists of some 30 innocent children and a teacher early on Saturday morning in a school in Mamudo town in northeastern Nigeria," said EU diplomatic chief Catherine Ashton in a statement.
Ashton promised Nigerians her "solidarity and determination to help them bring security, peace and reconciliation to the north", and called for those responsible to be brought to justice.
Survivors of the dawn attack said gunmen rounded up students and staff at the school in Nigeria's restive northeast and placed them in a dormitory before throwing explosives inside and opening fire.
A hospital official in nearby Potiskum said 42 people were killed. A spokesman for Nigeria's military, which often underplays casualty figures, said 20 students and one teacher were killed.
Boko Haram, which means "Western education is a sin", has killed hundreds of students in attacks on schools in the region in recent months.
Nigeria launched a major offensive against Boko Haram on May 15, and has declared a state of emergency in three flashpoint states including Yobe, the scene of Saturday's attack.