Three people were killed and 21 injured when a blast went off inside a residential area in Lahore, capital of Pakistan's eastern Punjab Province on Wednesday, Dawn News reported. 

Those wounded by the powerful blast included local residents and some police officers who were manning a checkpoint set up next to the house of Hafiz Saeed, founder of Islamist militant group Lashkar-e-Taiba (LeT).

"Apparently what we see is that our law enforcement agencies are the target," provincial police chief Inam Ghani told reporters. 

Five of the injured were in critical condition, according to the report.

The nature of the blast has not been determined yet. A bomb disposal squad and gas pipeline workers rushed to the site to secure gas lines and investigate the cause of the explosion.

No one has claimed responsibility for the bombing yet.

The blast damaged three cars and two nearby houses, causing acute panic among residents.

A fire erupted at the site following the explosion, and firefighters were trying to douse it, the reports said.

(With input from Xinhua, Reuters)