The blast occurred during the process of disposing of explosive waste with the help of a remote control at the Central Security Institute Ordnance Factory located in Khamaria in Jabalpur.

Disposing of explosive waste is a routine exercise at the Ordnance Factory, a unit that operates under the Ministry of Defence. The unit produces explosive devices for the Indian Army.

A hydraulic system reportedly malfunctioned during the bomb-filling process in building 200 of the factory's F-6 section, causing the blast, said officials.

Residents living near the factory said they thought it was an earthquake and many also ran out of their homes.

"The incident occurred when explosive waste was being disposed of with the help of a remote control. The blast took place in it which blew off some window glasses of an engineering section building around," OFK's Additional General Manager Sanjeev Gupta said.

The explosion was so intense that the building was reduced to rubble and the sound could be heard as far as five kilometres away. Injured people, who are employees of the factory, have been rushed to a private hospital for treatment, said the officials.

Four of the injured employees were shifted to a private hospital where they received stitches, according to information.

One person is said to be missing and may be trapped beneath the debris at the location, reports emanating from the depot mentioned.

District administration and police have rushed to the spot. The explosion is said to have occurred around 9.45 a.m. A probe is underway and rescue teams are active,, said the officials.

Further details are awaited.

The Ordnance Factory is one of the major ammunition production units under the Department of Defence Production. The factory is spread over a large area of 259 hectares, the Explosive Depot 303 hectares and the Estate 1,430 hectares. The factory was set up in 1943 and after Independence, the product range was diversified to meet the operational requirements of different Services and Para Military Forces. The present production activity of the factory is a combination of Hardware Component Manufacturing, Explosive Filling and Ammunition Assembly.