According to Russian authorities, who call the incident an act of terrorism, five to six perpetrators opened fire on two churches, a synagogue and a police post before being shot dead.
A film clip shows several people shooting with automatic weapons in the sub-republic’s capital, Makhachkala.
Another clip shows how a synagogue is on fire in the city of Derbent, which is further south.
The Russian Jewish Congress says gunmen threw Molotov cocktails and fired at police and security personnel deployed outside the synagogue after the Makhachkala airport was stormed last year, the Moscow Times reports.
Putin has not commented on the attack
So far, no one has claimed responsibility for the attack. Russian President Vladimir Putin has not commented either.
The population in the area has great diversity, but the majority identify themselves as Muslims, writes Reuters citing statistics from Russian authorities.
The incident occurs just over three months after the terrorist attack on the Moscow concert hall in which over 140 people were killed, which the terrorist organization IS claimed responsibility for.
Independent analysts believe that the incident is another sign of how blinded the authorities are to domestic Islamist violence, writes AFP.
See more about the event in the clip above.