A gas leak in northern India has killed at least 11 people.

Women and children were among those killed in the Punjab state port city of Ludhiana. A number of persons were discovered unconscious in their homes.

After numerous reports of breathing issues, the area was cordoned off and occupants were evacuated. Four people are being treated in a hospital.

So far, the source of the leak is unknown. According to one authority, the gas may have spread from manholes.

According to the PTI news agency, Ludhiana Deputy Commissioner Surabhi Malik, “we are going to collect samples from manholes.” It is very possible that methane was reacted with a chemical in manholes.”

According to Rajinder Pal Kaur Chhina, a local politician, the event occurred outside a milk business. “People who came to buy milk in the morning passed out outside,” she explained.

A team from the National Disaster Response Force has been dispatched to the scene in Ludhiana’s Giaspura neighborhood. There are several factories nearby.

In India, industrial gas leaks are not uncommon.

A gas leak at a chemical facility in Visakhapatnam, Andhra Pradesh, killed at least 12 persons three years ago.

A chemical leak in a pesticide facility in the central city of Bhopal killed thousands of people in 1984, in what is widely considered the world’s worst industrial disaster.