OUAGADOUGOU — Gunmen killed about 15 people in an attack on a mosque in Burkina Faso during prayers on Friday evening, a security source and a local official told Reuters.

The gunmen entered the mosque in the village of Salmossi, in the north of the West African country, and opened fire, the two sources said on Saturday. Others were seriously wounded, the security source said.

The identities of the gunmen were not yet clear.

Islamist insurgents with links to the Islamic State and Al Qaeda have crossed into Burkina Faso this year from neighboring Mali, igniting ethnic and religious tensions, especially in northern regions.

The attacks have shattered a relative calm in Burkina Faso, which, until this year, had largely been spared the kind of violence that has made large parts of the Sahel region ungovernable, especially Mali.