Dagestan, in the mainly Muslim North Caucasus region, is beset by frequent bomb attacks like this one las week [AFP]

A car bomb has killed one policeman and seven civilians in Russia's Dagestan region, authorities and local media say.

Wedensday's attack took place in the village of Hajjalmakhi, about 60km southwest of the provincial capital Makhachkala.

"As a result of the car bomb one policeman was killed, along with five civilians who were travelling past in another vehicle," a source in the regional Investigative Committee told the Reuters news agency, speaking on condition of anonymity.

Radio station Ekho Moskvy said two more civilians were killed, including an 11-year-old girl.

Upon discovering an empty "suspicious-looking vehicle" parked on the village outskirts, police started to conduct a search when it burst into flames, a law enforcement source told Interfax news agency.

Dagestan is beset by near-daily shootings and bomb attacks, blamed on Muslim fighters across the North Caucasus arising from two separatist wars in Chechnya and the high levels of poverty in the area.

Last week, three car bombs killed six people and armed men killed four more, including a high-level law enforcement official, in the region wedged between Chechnya and the Caspian Sea.

The fighters say they wan a separate Islamic state ruled by sharia law in the mainly Muslim North Caucasus region on Russia's southern frontier.

Dmitry Medvedev, the Russian president, has called the unrest the country's main security threat in the year before the March 2012 presidential election, which will see Vladimir Putin, the incumbent prime minister, seek a return to the Kremlin.

Source: Agencies