Sarkar served in the United Nation mission to the former Yugoslavia . He was appointed the Director General of Rapid Action battalion on 24 April 2005 , he replaced Anwarul Iqbal the first Director General of RAB . He served as the Director General of Rapid Action Battalion till 30 October 2006 . He served during the 15 August 2004 Grenade attack on Sheikh Hasina . He led RAB into arresting Mufti Hannan . Home Minister Lutfozzaman Babar expressed dissatisfaction over the arrest and asked him not investigate the issue further . He along with Colonel Gulzar Uddin Ahmed interrogated Mufti Hanan in the Taskforce for Interrogation Cell . Sarkar said due to his term being over he could not take any more action over the issue
15 August 2004 Grenade attack
2004 Dhaka grenade attack
Abdul Aziz Sarkar