Delhi blast: Agencies still clueless about even explosives used

As investigators grappled for leads on Wednesday's Delhi high court blast, not much headway was made into deciphering the deadly components of the bomb.

Sources in know of the investigation process told IANS that forensic reports from four labs have given different accounts on the explosives used in the blast.

They have agreed that some nitrate based substance was used for the bomb, but there is no clarity on the exact compound.

The reports, according to sources, have separately suggested the presence of PETN (pentaerythritol tetranitrate), nitrate components and some fuel. But there is no consensus.

On Wednesday, Secretary (Internal Security) UK Bansal had said that traces of PETN had been recovered from the blast site.

However, he had said that the explosive traces found were not conclusive.

PETN is one of the most powerful explosives and is difficult to detect. Because of its plastic nature, the explosive can easily pass metal detectors. Even bomb-sniffing dogs cannot detect it because of its low pressure molecules.

The explosive allows terrorists to use only small quantities for causing enormous damage. Even 100 grams of PETN is enough to blast away a car.

The Delhi High Court blast claimed 13 lives and left around 90 injured.