At least two policemen, a Rangers official and a factory worker lost their lives on Tuesday when a large cache of explosive material was accidentally triggered at a cement factory in Sukkur while officials were trying to deactivate it.

A Rangers press release late Tuesday said 226 kilograms of explosives, 3,064 safety fuses, 2,940 metres detonating chord and 2,668 detonators were found in and around Rohri cement factory during a search operation ahead of Muharram.

The material exploded while a police bomb disposal squad attempted to deactivate it. Seven Rangers personnel, two policemen and four factory workers were injured in the blast, Rangers said.

Seven critically injured in the blast were shifted to Karachi via a special Navy aircraft, while joint investigations are underway.

The explosives were to be used in the breaking down of large stones, which as part of the cement-making process.

Correction: It was earlier reported that Bomb Disposal Squad in-charge Malik Tahir had lost his life in the incident. However, police later confirmed four deaths while saying that Tahir is critically injured and has been shifted to Karachi for treatment. The error is regretted.