The explosive substance that was used in the deadly twin blasts in the city on Saturday evening was manufactured at Nagpur in Maharashtra, a forensic expert said on Sunday.

It was Neogel-90, an ammonium nitrate-based emulsifier explosive that was manufactured in Nagpur by a company named Omni explosives, he said.

The expert said the bomb that was defused at Dilsukhnagar was fitted with the explosives and metal balls.

Asked about the explosive substance, city police commissioner Balwinder Singh said it was too early to arrive at a conclusion.