"I am hurt with the deaths of people after a blast in a firecracker factory in Punjab's Batala. I express my deep condolence to the family of those killed in the accident and wish for the speedy recovery of those injured," Gandhi said in a tweet.
At least 21 people were killed and 26 injured in an explosion following a blaze at an unauthorised firecracker manufacturing unit in a densely-populated residential area in Batala town of Gurdaspur. The dead included the firecracker manufacturing unit's owner and six of his family members.
Seven grievously injured were referred to the Guru Nanak Hospital in Amritsar.
A number of nearby buildings, including a car workshop, were badly damaged in the explosion. An elderly woman and her grandchild, who were passing close to the disaster spot, were among the dead.