Six TV and radio broadcasting stations have been attacked overnight in Russia's North Caucasus republic of Kabardino-Balkaria, local media reported Sunday.

The explosions or fires occurred at various districts of republic, causing neither casualties nor disruption of normal operation of the stations.

Around 02:54 a.m. Moscow time (2254 GMT Saturday), two TV and radio relay stations were blasted in the Elbrus district. At 03:00 a.m. Moscow time (2300 GMT Saturday), a repeater of the Tyrnyauz radio station was blown up in the area of the Tyrnyauz ore-concentration combine.

Some ten minutes later, another repeater of the same radio station was set on fire in the village of Terskol.

Arsonists meanwhile set ablaze some relation stations in the Sarmakova village of the Zolsky district and in the city of Baksan.

It was not clear whether all these attacks were interrelated, as well as the reasons behind them.

An investigation was currently underway.

Meanwhile a car bombing hit the city of Chegem, with no casualties reported, but some property damage to a nightclub called Nebo because of the flames triggered by the explosion.

On May 23, local police foiled a major terrorist act in the city of Tyrnyauz, seizing a home-made explosive device equivalent of 1 kg of TNT at the Eternal Flame Memorial in the city center.

Violence is common in Russia's mainly Muslim North Caucasus republics, especially Chechnya, Dagestan and Ingushetia, with militants frequently targeting police and officials taken as representing the Russian authorities. Moscow recently made economic improvements in the region to prevent locals from joining terrorists.

Kremlin claimed to tackle the problem of unemployment, clan rivalry and corruption as these are viewed as the reasons for violence in the region.