Earlier in the day, AP reported, citing witnesses, that the blast injured 30 people.
Shiite leader Khawar Shafqat confirmed the incident but did not provide any further details.
A video emerged online, showing ambulances arriving at the scene of the explosion.
The explosion reportedly occurred outside the Mohajir Colony Mosque.
According to another report, the death toll from the blast currently stands at 5, with more than 40 people injured.