The Islamic State West Africa Province have executed 11 captives, mostly Christians, weeks after it killed aid workers.

Ahmad Salkida, a conflict journalist renowned for his monitoring of terrorist activities in Nigeria’s northeast, said ISWAP the captives were executed “as a revenge for the killings of our leaders, including Abu Bakr al-Baghdadi and Abul-Hasan Al-Muhajir in Iraq and Syria.”

But conflict journalists and researchers, including Jacob Zenn, said “it is possible IS ordered ISWAP to kill them.” as it had intervened in other hostage situations.”

He, however, debunked claims by the terrorist group that all victims are Christians.

“Not all 11 of the victims are Christians as claimed by the group, there were three Muslims and 10 Christians that appeared in the captured video on the 17th December,” Salkida said in a post on his website.

“The terrorist group claimed that they spared the lives of two persons that appeared in the earlier video, but did not give their names.

“However, a careful assessment of the video revealed that Suwaiba Kashimu from Nasarawa state, and one other male, were apparently not amongst those killed on Christmas,” Salkida wrote.

“The decision to execute the captives was rather swift, abrupt and shocking. ISWAP had reportedly opened a window of negotiations ostensibly to exchange the freedom of the captives with those of its members in government custody but the Nigerian government failed to take the offer.”

The killing comes few hours after Boko Haram jihadists killed seven people on Christmas Eve in a raid on a Christian village near the town of Chibok in northeast Nigeria’s Borno state.

Dozens of fighters driving trucks and motorcycles stormed into Kwarangulum late Tuesday, shooting fleeing residents and burning homes after looting food supplies.

Boko Haram and its IS-affiliated Islamic State West Africa Province (ISWAP) faction have recently stepped up attacks on military and civilian targets.