Britain's government says it will ban membership in the Nigerian Islamist radical group, Boko Haram, under its anti-terrorism laws.
Britain's Home Office says it is adding the group to its list of outlawed organizations, a move that will make it a criminal offense in Britain to belong to or support the group. The step must be approved by parliament before it can take effect.
Boko Haram has been blamed for many attacks across Nigeria since 2009, including one on Saturday in which gunmen massacred at least 30 people at a boarding school.
Survivors of the attack in Yobe state say the assailants set buildings on fire and then shot students as they tried to escape.
Yobe Governor Ibrahim Geidam said all schools in the state will be closed until September so authorities can figure out better ways to protect students and teachers.
Boko fighters are known to have attacked schools in the past.
The U.N. Children's Fund
, UNICEF, says a total of 48 students and seven teachers have been killed in northeastern Nigeria since June 16.
Human Rights Watch says more than 3,600 people have died since 2009 in Boko Haram-related violence, including alleged extrajudicial killings by Nigerian security forces.
Yobe is one of three states where President Goodluck Jonathan has declared a state of emergency and deployed troops to fight the militants.