As the Soviet armies of the 1st Belorussian Front and the 1st Ukrainian Front converged on the centre of the city there were many accidental 'friendly fire' incidents involving artillery shelling because the spotter planes and the artillery of the different Soviet Fronts were not coordinated and frequently mistook assault groups in other armies as enemy troops. Indeed, the rivalry between the Soviet armies to capture the city centre was becoming intense. A corps commander of the 1st Ukrainian Front joked with laconic humour, "Now we should be scared not of the enemy, but of our neighbour...