Moscow, Russia (CNN) -- Five repair workers were killed and three police officers injured Thursday when a roadside bomb exploded in the Russian republic of Dagestan, the Investigation Committee of the Russian Prosecutor's Office said.
The information posted on the committee's website differed from earlier media reports that the explosion killed eight people.
"According to preliminary findings, a [roadside] bomb exploded as a vehicle carrying repairmen was passing by ...," the website statement said. "Five workers died, and three policemen who were accompanying them, were injured."
The statement said the repairmen were heading to fix a mobile telecommunications transmitting antenna that was burned down by vandals Wednesday night.
The Interfax news agency reported that the attack occurred in the Segolinsky region of the southern republic.
Dagestan borders Chechnya, where insurgents seeking independence have been involved in a long-running and violent battle.
Last month, a suicide bomber killed two officers and wounded four others outside a police station in the neighboring republic of Ingushetia, authorities said. That attack was followed by a car bomb that hurt seven police officers and a civilian.
Both Dagestan and Ingushetia have seen an increase in violence in recent years -- a spillover from the Chechnya conflict.
Rebels say the upsurge in attacks is retribution for the Kremlin's violence and arbitrary rule in the region, and have promised "new acts of vengeance" in Russia.