MOSCOW  - A double car bombing in Russia's troubled North Caucasus killed at least 14 people and injured more than 120 just days before Vladimir Putin returns to the Kremlin, officials said Friday.The attacks late Thursday outside Dagestan's main city, which authorities said may have been triggered by suicide bombers, were the deadliest in the Caucasus in months and smashed any illusion of increasing stability.The power of the blasts sent huge yellow flames into the night sky, reduced cars to burned wreckage and left a crater in the ground, television pictures showed. A representative of the regional health ministry told AFP that 13 people died on the spot while another victim died later in a hospital. One more person is considered missing, said a health ministry official. Another 122 people were injured, and 83 were hospitalised, the emergencies ministry said.  Investigators said the first blast went off on the outskirts of the city of Makhachkala when a car laden with explosives was detonated near a traffic police post at 10:10 pm (1810 GMT) damaging nearby buildings and cars but causing no fatalities.The second car bomb went off 15 minutes later hitting policemen, rescue workers and passers-by who had gathered at the scene, investigators said.Regional police said in a statement that the first blast went off when a suicide bomber parked and detonated his vehicle near the traffic police post.A representative of the Dagestan regional investigators, speaking to AFP, refused to confirm the report but said investigators believed that a suicide bomber caused the second blast when he drove a vehicle into the crowd.The force of the second blast was equal to around 100 kilograms of TNT equivalent, police said.State television said it appeared that the initial blast was aimed at attracting emergency workers and security forces to the scene who were then hit by a more powerful second explosion.The regional health official said authorities had found one female foot and two male feet at the scene of the blast, adding that the two suicide bombers might be among the dead.The twin attacks appeared to bear the hallmarks of bombings conducted by radical militants fighting the Kremlin in the Caucasus where they seek to establish an Islamist state.The blasts were by far the deadliest attacks in the Caucasus this year and deal a huge blow to Kremlin hopes of restoring relative stability to a region that has been a headache for Moscow since the collapse of the USSR.Medvedev's administration said the president had tasked the head of Dagestan, Magomedsalam Magomedov, with rendering all necessary assistance to families of those killed and wounded.Putin once said "I sometimes feel sorry" for the militants because of the lack of opportunities available to them in the impoverished Caucasus. The Kremlin fought two wars against separatist rebels in Chechnya in the 1990s but the insurgency has now become more Islamist in tone and has spread to neighbouring regions such as Ingushetia and Dagestan.