A car bomb which exploded early on Tuesday in the capital of Russia`s North Caucasus republic of Dagestan could have been set off by a suicide bomber, the republic`s Interior Ministry said.

According to updated information, four police officers and a civilian were injured in the blast which occurred at about 04.40 Moscow time [00.40 GMT] in the outskirts of Makhachkala.

"Four policemen and a civilian were brought to a hospital with various injuries. Preliminary data indicates that the bomb was placed in a Lada passenger car and could have been set off by a suicide bomber," the ministry`s official told RIA Novosti.

An investigation is underway, the source said.

Dagestan`s Interior Minister Ali Magomedov later said police prevented a major terrorist attack because the suspected suicide bomber planned to set off the explosive device in a public place in the capital`s downtown.

Russia`s North Caucasus regions have seen a rise in violence in recent months. Attacks on police, officials and troops, and special operations against militants have been reported almost daily in Dagestan, Chechnya, and Ingushetia.

In June, Dagestan`s interior minister was assassinated at a wedding reception.
sections: World News