Leaders of Niger, Nigeria, Chad and Benin on Tuesday announced plans to step up the fight against Boko Haram with an additional battalion and a command centre to tackle the militants whose insurgency has spread beyond Nigeria, a statement said.

Boko Haram’s violent five-year campaign for an Islamic state has killed thousands and is threatening the stability of countries in the West and Central African regions.

In the past two months, it has progressed from bombings, raids and kidnappings to trying to seize territory in remote areas near the Cameroon border, possibly inspired by similar moves by Sunni Islamist militants in Iraq and Syria.

The militants have also carried out incursions into Niger and Chad, and authorities fear the attacks will continue to spread if left unchecked.

The four heads of states and a representative of Cameroon’s president said after meeting in Niger’s capital Niamey that a command centre for an already agreed-upon multinational force, led by a chief of staff will be in place by Nov. 20.

“The heads of state regrets the persistence of Boko Haram Islamic sect’s atrocious acts of terror on people and security forces in Nigeria and other neighbouring countries,” the statement said.

The leaders agreed to finalise the deployment of troops promised by member states to form the multinational force within their national borders by Nov. 1.

Benin, Nigeria’s western neighbour, whose border stretches from the Atlantic to the Sahel north, was also asked to deploy a military battalion to its border with Nigeria.

The Niamey meeting is a follow-up to a May summit in Paris where the leaders promised to improve cooperation in the fight against Boko Haram after the group kidnapped more than 200 schoolgirls and threatened to destabilise the wider region.