Addis Ababa, Ethiopia: UN secretary general Ban Ki-moon has backed the proposal of the African Union (AU) to send a regional force to stop the advancement of the ‘murderous campaigns’ waged by Boko Haram, emphasising that “lives depend on preventive-diplomacy and peacekeeping”, reports UN News Centre.

Support for the initiative, announced on Saturday at an AU summit being held in Ethiopia's capital Addis Ababa, came amid an upsurge in fighting with the group that has also drawn in Nigeria's neighbours.

The Chadian military said three of its soldiers and 123 rebels had been killed in two days of fighting in northern Cameroon.

Chadian planes then bombed the Nigerian town of Gamboru on Saturday, Al-Jazeera reports.

Ban pronounced Boko Haram indispensable to be ‘addressed with an informal and general co-operation’.

“I acquire a preference of an AU and informal countries to settle an MJTF [Multinational Joint Task Force] opposite Boko Haram,” he told reporters.

“They have committed accursed brutality. Not a singular country, even informal countries, can hoop this alone,” he added.

“The United Nations is prepared to entirely co-operate with an African Union.”

Ban but pronounced that “military means might not be a usually solution”.

“There should be really clever research of a base causes because this kind of terrorism, and extremism, aroused extremism, are spreading,” he said.