Attack in Russia's Dagestan province kills 8

A bomb blast hit a police-escorted vehicle carrying repair workers sent to fix a communications tower that had been damaged in a sabotage attack overnight, the Russian prosecutor general's office said.

Most or all of the eight people killed in the attack, about 80 km (50 miles) south of Dagestan's capital Makhachkala, were believed to have been repairmen, a provincial Interior Ministry spokesman said. Four police officers were wounded.

Hours later, police were still exchanging fire with the attackers, he said.

Dagestan, adjacent to Chechnya in Russia's heavily Muslim North Caucasus, is plagued by daily violence including frequent attacks that target law enforcement officials.

Authorities blame most of the attacks on Islamic militants, but some violence is connected to organised crime and to clan rivalries. Most Islamic militants are separatists.

Russian authorities blame female suicide bombers from Dagestan for twin blasts that killed 40 people in Moscow's metro on March 29. The Chechen leader of the main militant group in the North Caucasus claimed responsibility for the attack.

Suicide bombers in killed 12 people in Dagestan two days later, most of them police.

Dagestan, Chechnya and neighbouring Ingushetia have suffered increased violence in the past two years, a decade after federal forces drove separatists from power in Chechnya in the second of two post-Soviet wars.

(Writing by Steve Gutterman; editing by Angus MacSwan)