Isis failed to build dirty bomb because 'they aren't that smart'

Isis was sitting on the main ingredient for making a radioactive dirty bomb in Mosul for more than three years, but was either unaware or unable to utilise the technology for its own purposes, it has emerged.

The extremist Sunni group overran the Iraqi city after sweeping across the border from Syria in 2014. As the army abandoned their posts, weaponry and tanks came into their possession - but Western intelligence officials were also worried that the cobalt-60 isotope used in radiotherapy treatment machines in medical facilities would fall into their hands, the Washington Post reported Sunday.

Cobalt-60 is in theory the main component in a radiological dispersal device (RDD), or ‘dirty bomb’ - radioactive material combined with conventional explosives.

However, two caches of the substance in a storage room on a university campus were discovered untouched by Iraqi coalition forces last month during the battle to liberate the city, health officials said.

“They [Isis] are not that smart,” one health ministry official told the Post.

It is not clear why Isis failed to use the cobalt - which exposure to can deliver a fatal dose of radiation in less than three minutes.

Given the fighters thoroughly ransacked the city and it was reported in July 2014 had come into the possession of low-grade unenriched uranium, it is unlikely they did not find the cobalt stores. Instead, the substance may have proved too difficult to extract without exposing militants themselves to harmful doses of radiation, nuclear experts told the Post.

Officials have still insisted the radioactive material's location remain secret, however, fearing Isis could still get hold of it.

After nine months of brutal fighting, the US-backed Iraqi coalition Operation Inherent Resolve to oust the militants from Mosul is in its final stages.

Thousands of civilians have been killed in crossfire, used as human shields or have died in US-led coalition bombing, and almost one million people in total were forced to flee their homes.

Iraqi troops are still sweeping the city for sleeper cells, wary of counter suicide bomber attacks.

Fears that terrorists will utilise a dirty bomb to cause mass panic and disruption to civilians have been heightened since the attacks of 9/11. While dozens of people across the world have been arrested on suspicion of collecting materials to create a dirty bomb in recent years, no such device has been utilised to inflict harm on the public to date.