Officials said a bomb disposal squad had defused an explosive device which weighed 12 kilogrammes and could have caused lot of havoc if detonated.
The device was found in a plot next to the Rangers' Sachal Wing headquarters near a highway.
Besides 12 kg of explosives, the bomb also carried ball bearings and was made in an oil canister.
A Rangers official said it is too early to comment on whether the bomb was intended to target the Rangers.
"We will wait till the investigation into the matter is completed," he said.
In the past, militants have targeted security forces and police installations in Pakistan's biggest city.
