Eleven people died and nine were hospitalised after a gas leak in Ludhiana in the northern Indian state of Punjab, a state lawmaker said on Sunday.

A team from the National Disaster Response Force was at the site along with a team of experts to determine the cause and source of the leak, said Rajinder Pal Kaur Chhina, a member of the legislative assembly in Ludhiana.

Police officials were seen patrolling wearing masks and asking locals to keep out of a cordoned area, according to ANI news agency’s video feed on Twitter.

“The incident happened near a milk shop and a doctor’s clinic although we cannot say for sure where the leak began,” Chhina told Reuters by phone.

“People who came to buy milk in the morning fell unconscious outside,” she said.

Punjab Chief Minister Bhagwant Mann tweeted the leak was from a factory, without providing further details.

“Definitely, it is a gas leak case. The NDRF team is present at the spot to evacuate the people and will conduct the rescue operation,” ANI quoted West Ludhiana Sub Divisional Magistrate Swati as saying.

ANI said a fire brigade team was also present at the site while the police have sealed the area.

A video shared by ANI on Twitter showed a local saying, “I came to know that five members of my family are unconscious.” In the video, police officials could be seen stopping him from going towards the incident site.

Another video showed a resident, Anjan Kumar, telling the reporter that the gas leaked from the factory was poisonous and one “would not be able to breathe” when surrounded by it. Three bodies had “turned blue”, he said.

In August 2022, at least 112 women had been hospitalised after a gas leak occurred at an apparel manufacturing plant in India. However, no deaths were reported at the time.

In May 2020, at least five people were killed and hundreds were hospitalised after a gas leak at a chemical plant in Visakhapatnam, an industrial port city in Andhra Pradesh.