What role did Zia ur-Rahman play in the resistance during the Bangladesh Liberation War?

During the Bangladesh Liberation War, Zia ur-Rahman played a significant role as a leader of the internal resistance against the Pakistani army.1

Following the launch of the Pakistani military's attack on March 25, 1971, Zia, then a major, held out against the Pakistani forces in Chittagong for several days. After the town was recaptured by the Pakistani army, he retreated to the border region, where he began organizing bands of guerrillas to continue the fight for independence. His efforts were part of the broader mobilization of resistance by Bengali units of the regular army following the declaration of independence by the Awami League leadership.1