Initially, the Russians were taken by surprise. Their armoured columns that were supposed to take the city without difficulty as Soviet forces had taken Budapest in 1956 were decimated in fighting more reminiscent of the Battle of Budapest in late 1944. As in the Soviet assault on Berlin, as a short term measure, they deployed self-propelled anti-aircraft guns (ZSU-23-4 and 2K22M) to engage the Chechen combat groups, as their tank's main gun did not have the elevation and depression to engage the fire teams and an armoured vehicle's machine gun could not suppress the fire of half a dozen different fire teams simultaneously.