A series of bomb blasts in Russia's North Caucasus region of Daghestan have killed a militant and the wife of a local security officer, and left others wounded.

Citing local police reports, Russian news agencies say a suspected Islamic militant was killed in an apartment in the capital, Makhachkala, when a bomb he was making accidentally exploded.

A separate car bomb in the city later killed the wife of a colonel in the local branch of Russia's Federal Security Service (FSB).

The colonel was also injured in the blast.

A third blast outside a Makhachkala shop late on April 15 injured two female students.

The latest explosions are part of a pattern of steady violence and attacks in the North Caucasus fed by an Islamic insurgency, clan feuds, and business disputes.