An operation against militants in Dagestan has left at least four Russian commandoes dead.The officers were storming two houses in the city of Makhachkala where five rebels were holed up. The militants, thought to have been hiding in the basements of the houses, are presumed to have been killed after the properties were destroyed by tanks and fire. Dagestan borders Chechnya and violence has often spilled over from there in years of fighting between Russian forces and separatist rebels. The militants barricaded themselves inside the houses after being tracked down by police. They let the occupants go, telling them they were fighters of islam. Also on Saturday, in a separate storming in a nearby town, it is reported two soldiers and one rebel were killed and four militants were captured.