The army says Nigerian soldiers have killed 79 militants and suspected kidnappers over the past week in an operation targeting a decades-long insurgency by Islamic militants in the northeast and attacks by various armed groups in the northwest.

At least 35 Nigerian soldiers have been killed in the line of duty over the past three weeks, underscoring the significant challenges the military faces in combating an insurgency.

A jihadist suicide attack kills 27 Nigerian soldiers, including the commander, in the Timbuktu Triangle, as ISWAP militants target troops in the northeast.

Eighteen people were also killed in a truck accident in south-eastern Nigeria on Sunday, a week after a petrol tanker explosion left at least 98 dead.

Suspected Islamist fighters killed at least 20 Nigerian soldiers, including a commanding officer, after attacking an army base in a remote town in northeastern Borno state, security sources and residents said Sunday.