Two strong blasts tore through a supermarket in Russia\'s volatile Caucasus region of Dagestan, injuring 18 people, Itar Tas said on Monday. The news agency reported that the first blast went off late on Sunday and wounded a sales clerk, the second struck when a Russian security team arrived on the scene. There was no immediate claim of responsibility for the attack. The Caspian Sea region of Dagestan experiences almost daily shootings and bombings that officials blame on local criminals and Islamists with links to Chechnya. Fuelled by endemic poverty and corruption, the militants are seeking to establish an independent Islamic state across the North Caucasus.