A double car bombing in Russia's troubled North Caucasus region killed 12 people and wounded more than 100, authorities said Friday.

Two car bombs exploded late Thursday at a police checkpoint near Makhachkala, the capital of the Dagestan region, which is the site of a long-standing Islamic insurgency.

The National Anti-Terrorist Committee said the first blast took place when police stopped a vehicle at the checkpoint, and the second explosion happened within minutes, when the fire brigades and ambulances were at the blast scene, Reuters reported.

According to a witness, a fire truck was charred completely, and only its wheels remained whole. Russia's Interfax news agency said fragments of human bodies were scattered at the post.

The AFP reported that the attacks bore the hallmarks of an Islamist militant attack. Reuters said local investigators had found the remains of a man and a woman suspected of being the suicide bombers.

Thursday's attacks were the deadliest militant strike in the Caucasus region this year and come just three days before Vladimir Putin, who had made fame by sending troops to Chechnya to suppress Islamic separatists more than a decade ago, swears in as President.

The Caucasian militant movement, which aims to create an Islamic state in the region, had claimed responsibility for a suicide bombing at Moscow's Domodedovo airport last year and the Moscow metro twin bombings that killed 40 people in 2010.

According to Reuters, Dagestan is the epicenter of the low-level insurgency across the mainly Muslim North Caucasus region, and shootings take place there almost every day.