Short answers, pulled from the story.
The Independent Operational Group Polesie emerged on the 11th of September 1939. General Franciszek Kleeberg received orders from Polish Commander in Chief to defend a specific region stretching between the Muchawiec and Prypeć rivers.
General Franciszek Kleeberg commanded the Independent Operational Group Polesie. He led the group from its formation until his surrender on the 5th of October 1939, becoming the last Polish general to capitulate during the defensive war.
The headquarters of the Independent Operational Group Polesie sat within the town of Pińsk. The area defended by the group stretched between the Muchawiec and Prypeć rivers before German forces broke through central defenses.
The final engagement began on the 2nd of October at the town of Kock against German XIV Mechanized Corps. Fighting continued through early hours of the 6th of October when supplies ran completely out including essential ammunition.
General Franciszek Kleeberg redirected his troops away from the Romanian border to assist Warsaw after finding himself cut off from superiors on the 22nd of September. His forces targeted the town of Dęblin where large stores of supplies existed before engaging Soviet Red Army forces.