Coimbatore : Four workers died of asphyxiation, while cleaning an effluent tank of a textile factory in nearby Tirupur today.

All the deceased were hailing from Assam and were identified as Abu, Anwar Hussain, Dilwar Hussain and Farooq Ahmed, aged around 20 years police said.

The workers were asked to get down the 20-feet deep tank and clean it, where the effluent was stored after washing the textile fabrics and garments, in Karuppagoundernpalayam in the city.

As one of them got down the tank and got suffocated, the other three entered to rescue him. However, all suffered suffocation, resulting in the death of three inside the tank, while another died on admission to the Government Hospital in Tirupur, they said.

The district revenue and police officials rushed to the spot and carried out an inquiry that revealed that the tank was not cleaned for the last four years, police said.