Eleven persons, including three children, died due to a gas leak in Giaspura area of Punjab’s Ludhiana on Sunday, PTI reported. Four persons have been hospitalised.

The source of the gas leak or its type remains unknown, reported The Indian Express.

The Punjab Police said they have sealed the area and deployed a fire brigade vehicle and an ambulance. A team from the National Disaster Response Force is also present.

Ludhiana Deputy Commissioner Surabhi Malik said that it is suspected that a chemical was disposed of in the sewage that reacted with methane, reported The Indian Express.

“It is likely that deaths happened due to gas contamination,” Malik said. “The teams are now going to collect samples from manholes...Those who have died have now shown any respiratory symptoms”

The district administration said that a compensation of Rs 2 lakh will be provided to the family of the deceased and Rs 50,000 each for those who were fell ill due to the gas leak, according to PTI.

Punjab Chief Minister Bhagwant Mann said that all possible help is being provided.

“The incident of a gas leak at a factory in the Giaspura area of Ludhiana is very sad,” he said in a tweet. “Police, government and NDRF teams are present at the spot.”

Union Home Minister Amit Shah also expressed grief at the loss of lives in the incident.