Seven women died during treatment on Sunday after being affected in a major ammonia gas leak at a private seafood processing unit in Manjangaranai near Periyapalayam, police said.

A total of 67 affected workers were rushed to local medical centres immediately after a major ammonia gas leak at a private seafood processing unit in Manjangaranai near Periyapalayam, Thiruvallur District Collector S Kavitha said, 46 are being treated at Vels Hospital and 21 at Venkateshwara Hospital.