Soviet attacks on the 4th SS Panzer Corps east of Warsaw were renewed on 26 August, and the Germans were forced to retreat into Praga. The Soviet army under the command of Konstantin Rokossovsky captured Praga and arrived on the east bank of the Vistula in mid-September. By 13 September, the Germans had destroyed the remaining bridges over the Vistula, signalling that they were abandoning all their positions east of the river. In the Praga area Polish units under the command of General Zygmunt Berling (thus sometimes known as berlingowcy – "the Berling men") fought on the Soviet side. Three patrols of his 1st Polish Army (Polish: 1 Armia Wojska Polskiego) landed in the Czerniaków and Powiśle areas and made contact with Home Army forces on the night of 14/15 September. The artillery cover and air support provided by the Soviets was unable to effectively counter enemy machine-gun fire as the Poles crossed the river, and the landing troops sustained heavy losses. Only small elements of the main units made it ashore (I and III battalions of 9th infantry regiment, 3rd Infantry Division).
General Berling Monument in Warsaw. In the background, Łazienkowski Bridge.
The limited landings by the 1st Polish Army represented the only external ground force which arrived to physically support the uprising; and even they were curtailed by the Soviet High Command.
The Germans intensified their attacks on the Home Army positions near the river to prevent any further landings, but were not able to make any significant advances for several days while Polish forces held those vital positions in preparation for a new expected wave of Soviet landings. Polish units from the eastern shore attempted several more landings, and from 15 to 23 September sustained heavy losses (including the destruction of all their landing boats and most of their other river crossing equipment). Red Army support was inadequate. After the failure of repeated attempts by the 1st Polish Army to link up with the insurgents, the Soviets limited their assistance to sporadic artillery and air support. Conditions that prevented the Germans from dislodging the insurgents also acted to prevent the Poles from dislodging the Germans. Plans for a river crossing were suspended "for at least 4 months", since operations against the 9th Army's five panzer divisions were problematic at that point, and the commander of the 1st Polish Army, General Berling was relieved of his duties by his Soviet superiors. On the night of 19 September, after no further attempts from the other side of the river were made and the promised evacuation of wounded did not take place, Home Army soldiers and landed elements of the 1st Polish Army were forced to begin a retreat from their positions on the bank of the river. Out of approximately 900 men who made it ashore only a handful made it back to the eastern shore of the Vistula. Berling's Polish Army losses in the attempt to aid the Uprising were 5,660 killed, missing or wounded.
From this point on, the Warsaw Uprising can be seen as a one-sided war of attrition or, alternatively, as a fight for acceptable terms of surrender. The Poles were besieged in three areas of the city: Śródmieście, Żoliborz and Mokotów.