Ivory Coast’s army said on Thursday it had identified a detained Burkina Faso national as the coordinator of a suspected jihadist attack that killed at least 13 soldiers this month.

The ambush on the night of June 10 on a military outpost in Kafolo was the deadliest since gunmen from al Qaeda’s North African branch stormed the beach resort of Grand Bassam in March 2016, killing 19 people.

In the wake of the latest attack, the army rounded up 30 suspected militants believed to have been involved, as well as weapons, motorcycles and telephones, the statement said.

“Among the combatants arrested was the Kafolo attack coordinator. He is called Sidibe Ali … of Burkinabé nationality,” it added.

On Monday, the defence minister had said those arrested included the suspected head of a jihadist group.

Last month, Ivory Coast and Burkina Faso launched a joint military operation called Operation Comoe to tackle the expanding threat from Islamist jihadists linked to al Qaeda and Islamic State in the Sahel region.

Mali, Niger and Burkina Faso have been worst hit by the militant violence, but there are concerns that the attacks could spread to coastal nations.