Police said that the powder was bought from a quarry in Bharuch, and a team will be sent soon to speed up investigations.

Narmada Superintendent of police (SP) J R Mothlia said that Sanabhai Tudvi and his wife Jasiben, both daily wage labourers were arrested with four kilos of the substance.

“We received an intelligence tip off about the substance in Vasla and mounted a raid. We recovered some of the powder and arrested a couple. We will soon send a team to Bharuch to investigate the source of the powder,” Mothlia said.

Police said the powder was likely procured from one of the several quarries in Rajpardi in Bharuch.

Deputy Superintendent of Police (DySP) J A Patel said, “The Tudvis managed to buy at least 20 kgs of the powder, but claimed they have sold much of it to others in the area. We are trying to trace the buyers, while a team is investigating the illegal sale of the powder from the quarries.” The Tudvis have been booked under the Explosives Act and were produced in court on Monday evening.

According to sources in the Narmada Police, Ammonium Nitrate is used only for fishing purposes, and not towards any terrorist activity. Senior police officials said fishermen generally place a charge of the explosive underwater in sections of the Narmada River and lakes, as the process was easier than using nets to catch the fish.