Six people, including child, wounded in shootings in Russia's North Caucasus

Six people, including a child, have been wounded in three separate shootings in Russia's volatile North Caucasus republic of Dagestan, a local police official has said.

Two of the incidents took place in the republic's northern city of Khasavyurt, one late on Sunday and the other early on Monday, RIA Novosti reported.

In a first incident, a local prosecutor's aide and his minor son were wounded by unknown gunmen, the spokesman said. Both were taken to hospital.

A woman was wounded in a second shooting, when gunmen opened fire at a car carrying a police officer. The woman was just passing by.

Police is investigating the incidents, the spokesman said.

A third shooting, in which three police officers were wounded, occurred in the republic's capital, Makhachkala, early on Monday, local police said.

Sporadic terrorist attacks and militant clashes are common in Russia's southern republics in the North Caucasus, especially Dagestan, Chechnya, and Ingushetia.

The Kremlin has pledged to wage "a ruthless fight" against militant groups but also acknowledged a need to tackle unemployment, organized crime, clan rivalry and corruption as causes of the ongoing violence in the region.

Early on Sunday, a freight train loaded with grain was derailed after an explosive device went off at a railroad in Dagestan. A spokesman for the local Interior Ministry said there were no casualties in the blast.