Coimbatore (Tamil Nadu): Ammonia gas leaked from a closed chips manufacturing unit at Chenniveerampalayam village near Karamadai here, causing panic, following which authorities evacuated around 250 families from the area as a precautionary measure. The police gave this information on Tuesday.

Four years ago, a leak from a cold storage unit for potatoes at the export factory caused ammonia to dissolve in the air around midnight on April 29, causing some villagers to complain of eye irritation.

"Police immediately evacuated the families to a safe place and temporarily accommodated them in a marriage hall as a precautionary measure," a senior police officer said.

He said the unit exporting chips and French fries was recently sold and the gas leak might have occurred during renovation.

Police and fire service personnel who reached the unit closed the valve of the tank and prevented further damage.