Boko Haram is a threat to all - AU

The Boko Haram militants are a threat beyond Nigeria's borders and the crisis requires a "collective, effective and decisive response" by African nations, the African Union's Commission chief says.

"Terrorism, in particular considering the brutality of Boko Haram against our people, are a threat to our collective safety, security and development.

This has now spread to the region beyond Nigeria and requires a collective, effective and decisive response," AU commission chair Nkosazana Dlamini-Zuma said in a speech opening a two-day summit of African leaders in Addis Ababa.

UN Secretary-General Ban Ki-moon, also addressing leaders from the 54-member bloc, said Boko Haram was "a clear danger to national, regional and international peace and security".

"This group continues to kill Christians and Muslims, kidnap women and children, and destroy churches and mosques. We will never forget the girls and boys kidnapped from Chibok last April, I will never stop calling for their immediate and unconditional release," he said.

The African Union's Peace and Security Council called early Friday for the setting up of a regional five-nation force of 7,500 troops to fight the militants.