Introductory reports show that a truck stacked with organic products got went head to head with high pressure wires which caused the blast.
The explosion, reportedly, took place in a truck loaded with fruits.
In April, six persons were killed and 15 others injured when a suicide bomber targeted a population census team in Lahore's Bedian Road.
The injured were taken to Services and Mian Munshi hospitals from where 12 of them were discharged after first aid.
He maintained that police is investigating and nothing can be said about the nature of the explosion.
The incident has raised security concerns ahead of former prime minister Nawaz Sharif's planned rally to Lahore from Islamabad via the GT Road tomorrow.
The release said the State Department travel warning for Pakistan issued on May 22, 2017 remains active.
No group has yet claimed responsibility for the attack and it was not clear whether the militants killed were responsible for Monday's bomb blast but police officials said that they were not ruling out a connection.
DIG Haider Ashraf confirmed that it was a bomb blast and said that the blast has created a huge crater at the blast site.
The blast was so severe that it was heard in far flung areas in the city.
"Due the impact of the blast, I fell on the ground". The roof of a nearby house collapsed due to the intensity of the explosion, while the windowpanes of nearby buildings were also shattered.
Punjab Chief Minister Shahbaz Sharif has asked for a report from Capital City Police Officer Amin Wains.