At least 40 people were injured in an explosion on a Jamaat-i-Islami rally in Karachi on Wednesday, according to a media report.

The blast took place near the main truck that was part of the rally in Gulshan-i-Iqbal area, a JI spokesperson said.

East senior superintendent of police Sajid Sadozai said two unidentified persons riding a motorcycle threw an RGD-1 grenade at the rally and fled, Dawn News reported.

According to Meeran Yousuf, the media coordinator to the Sindh health minister, of the total, one person was stated to be in critical condition while no deaths were reported, the report further said.

The incident happened near a mosque and shattered windows of cars nearby. A heavy contingent of security forces reached the site after the incident.

Eyewitnesses said the blast caused a stampede and severely injured five people on the site, according to the Geo News report.

“The banned Sindhudesh Revolutionary Army (SRA) claimed responsibility for the attack through social media,” the Dawn said.

The JI rally was being held in connection with Youm-i-Istehsal (the day of exploitation), which is being observed to mark one year since India revoked occupied Kashmir’s semi-autonomous status on August 5.

Taking to Twitter, JI chief Sirajul Haq called the bomb attack a “cowardly act”.

Sindh government spokesperson Murtaza Wahab also condemned the attack, saying it a “conspiracy to disturb the peace of Karachi”.

In June, two Pakistan Rangers officials and a civilian were killed and three others injured in a blast in Sindh province.

Earlier this year, at least 16 people were killed and many injured after a bomb blast occured at a Counter Terror Department during evening prayers in southwestern Pakistan.

(With inputs from agency)