As Abdus Salam consolidated his position in the government and Munir Ahmad Khan returning to Pakistan from the International Atomic Energy Agency (IAEA) to lead the crash program, the efforts were transferred to the authority of the PAEC. The weapons development portion for this project was located at 20 special weapons' labs overseen by the PAEC. Development and designing took place with the foundation of the Theoretical Physics Group (TPG) led by Abdus Salam and Mathematics division led by Razi Siddiqui at PAEC; all engaging in the fast-neutron calculations. Physical developments were eventually carried out by "Wah Group Scientists" led by Hafeez Qureshi and Dr. Zaman Sheikh (a chemical engineer) at the Metallurgical Laboratory located in Wah in March 1974. Logistics and coordination between each secret site were overseen by the Directorate of Technical Development (DTD) under Zaman Sheikh.