Karachi: Two Pakistani policemen, having a smoke on a police station rooftop, casually stubbed the cigarette in a bottle containing highly inflammable chemicals for making explosives - causing a blast.
The explosion on the roof of Risala police station on Saturday afternoon was caused by two policemen who were smoking on the roof, officials of the bomb disposal squad (BDS) told The News.
Potassium nitrate, which is a chemical component in explosives and is inflammable, was stored in a container on the rooftop. The chemical is also known as saltpetre.
The team found that there were two bottles of potassium nitrate on the rooftop, each carrying 100 grams of the explosive material.
"One of the two policemen put a burning cigarette in the bottle carrying saltpetre. This caused a huge explosion, injuring both men," an official was quoted as saying.
The bottles had been sent to the Risala police by the BDS for testing purposes, after a large quantity of potassium nitrate had been discovered near the courts.
"Some 15 to 20 kg of potassium nitrate was recovered last year near City Courts premises. Except for some 200 grams, the rest was disposed of."
"Instead of sending the samples to the lab, the Risala police dumped these two bottles on the roof of their building," the official said.
The official went on to say that his assessment was that "the chemical was ignited by cigarette. Most probably, one of the guards put the burning end of the cigarette in the container, and this caused the explosion."
The explosion caused panic in the area with the people fearing it to be a terror attack.
Pakistan has been hit by a string of terror strikes as the Army continued its assault against the Taliban fighters in South Waziristan.