The suspects, Syed Raza Haidar Zaidi and Jameeluddin, were wanted for the murder of a police constable who was shot dead in 2001.
The accused were arrested from Liaquatabad Super Market, an area usually bustling with people. Two hand grenades and two pistols were also confiscated from their possession.
Liaquatabad Superintendent Police Saqib Ibrahim said four cases have been registered against the two.
Over the past year in particular, law-enforcement agencies have claimed comprehensive success in tackling serious crime in Pakistan’s largest city since the operation to restore law and order in Karachi began in late 2013.