(VOVworld) - The UN Security Council has said it is alarmed by ties between Nigeria's Boko Haram Islamist militants and the Islamic State group.

Boko Haram has sworn allegiance to IS and often displays its trademark black flag (Photo: bbc.com)

In a statement on Friday, it said Boko Haram - which pledged allegiance to IS in 2015 - continued to "undermine the peace and stability" in West and Central Africa, causing 2 million Nigerians to leave homes. Nigeria is to host a summit on Saturday on fighting Boko Haram.