A blast occurred in a high security area near the Cantonment railway station on Tuesday though no one was injured, police said.
A Sindh Police spokesman said that the blast which caused panic in the area was apparently caused by a leak in a gas or sewerage line.
A bungalow’s boundry wall was damaged in the explosion.
A team from the bomb disposal squad was sent to the site to determine the reason for the explosion.
Pakistan is reeling under a wave of bombings blamed on Taliban and al-Qaeda militants.