The country borders Mali, Niger and Burkina Faso, where a years-long jihadist campaign has claimed thousands of lives and driven more than two million people from their homes.

A posting Thursday on the government website said, "Nearly 20 or so attacks by armed groups against Benin, and the army has buried around 10 of its soldiers."

The report was an account of a ceremony in the capital Cotonou for five servicemen killed in an assault in the north last month.

"There is no longer any doubt, Benin is at war against terrorism," Vice President Mariam Chabi Talata told the ceremony, although the report made no mention of the term jihadist.

In another attack this month in northern Togo, eight soldiers and 15 attackers died in what the Lome government called the country's first deadly "terrorist" attack.

Benin's first known fatal attack was last December, in which two soldiers were killed near the troubled frontier with Burkina.

The government responded by announcing increased military deployment in the north to protect the border.

Armed incursions by jihadists linked to Al-Qaeda and the Islamic State (IS) organisation from troubled Sahel nations have also affected Ghana and Ivory Coast, strengthening fears of a southwards push from the Sahel towards the Gulf of Guinea.