At least 39 armed men have been killed and others wounded in two different operations by the Nigerian army in Zamfara state, northwest Nigeria this week, an army spokesperson said on Saturday.

The operations were carried out in Bakura and Anka axis of the state, Oni Orisan, an spokesman for "Operation Hadarin Daji" said in a statement.

He said 19 of the "bandits" were killed in an encounter with the army in the bushes of Anka while the 20 were killed in Bakura.

Orisan reiterated that the soldiers would not attack any repentant militants, and those unrepentant ones who carry guns and move around in large numbers would be treated as hostile.

He urged the unrepentant armed men to surrender their arms to constituted authorities and embrace the peace initiative of the state government.

A series of "bandit" attacks have been recorded in the northwest part of the west African country since the beginning of this year, leading to more troops and equipment deployed to the area.