Extremist militants in Iraq have seized nuclear materials that could be used in terrorist attacks, officials told the United Nations this week. However, the UN's nuclear watchdog described the material as "low-grade" and said it is unlikely to pose a significant risk.

In a July 8 letter sent to UN Secretary-General Ban Ki-moon and seen by Reuters, Iraq's UN Ambassador Mohamed Ali Alhakim said that almost 88 pounds of uranium compounds had been stored at a university in Iraq's second city of Mosul, and that they could be "used in manufacturing weapons of mass destruction." Mosul was overrun by hardline Sunni militants led by the Islamic State of Iraq and Syria (ISIS) when they made a lightning advance across large parts of northern Iraq last month

"These nuclear materials, despite the limited amounts mentioned, can enable terrorist groups, with the availability of the required expertise, to use it separate or in combination with other materials in its terrorist acts," Alhakim said, going on to ask the international community for help to "stave off the threat of their use by terrorists in Iraq or abroad."

'Any loss of regulatory control over nuclear and other radioactive materials is a cause for concern.'

The UN's International Atomic Energy Agency (IAEA) said today that the material involved was unlikely to present a major risk. "The IAEA is aware of the notification from Iraq and is in contact to seek further details. On the basis of the initial information we believe the material involved is low-grade and would not present a significant safety, security or nuclear proliferation risk," spokeswoman Gill Tudor said in a statement. She added: "Nevertheless, any loss of regulatory control over nuclear and other radioactive materials is a cause for concern." The IAEA declined to comment further when contacted by VICE News.

Human Rights Watch's Emergencies Director Peter Bouckaert told VICE News that serious nuclear materials probably wouldn't have been stored at the university due to Mosul's location in the most unstable part of Iraq. "It is most likely to be low-grade nuclear material used in university chemistry labs. We don't have any indication that the nuclear compounds seized from Mosul University would pose any significant threat," he said.

Bouckaert added that Alhakim's appeal was more likely designed to seek international intervention to help Prime Minister Nouri al-Maliki's central government in Baghdad, which is struggling to deal with the ISIS-led insurgency. "It would seem that the ambassador is more interested in gaining support for the beleaguered Maliki government and getting other countries to intervene on behalf of the government," he said.

Alhakim had previously written to the UN to inform them that ISIS-led militants had seized the Muthanna chemical weapons facility north-west of Baghdad last month. There they reportedly plundered a stockpile of old weapons, including degraded chemical rockets containing sarin nerve agent and a toxic precursor to tabun.

'The chemical weapons at the Muthanna factory pose almost no risk, except to anyone trying to enter the sealed tankers.'

ISIS overran the complex on June 11, but the US and UN downplayed any risk as the material dates from the 1980s. The bunkers were also heavily damaged by bombardment during the first Gulf War in 1991, then sealed up by UN inspectors who were unable to safely access them.

US State Department spokewoman Jen Psaki told reporters on June 20 that while officials were concerned about ISIS seizing the facility the material was unlikely to be usable. "It contains two bunkers that hold degraded chemical remnants, which don’t include intact chemical weapons — and there certainly is a difference — and would be very difficult, if not impossible, to safely use this for military purposes or, frankly, to move it," Psaki said.

In fact, Bouckaert explained, the chemical agents are likely to only prove dangerous to anyone stupid enough to break into the bunkers. "The chemical weapons at the Muthanna factory pose almost no risk, except to anyone trying to enter the sealed tankers... They would be extremely degraded and it would be virtually impossible to create usable CW agents, so anyone trying to do so would be taking a suicidal risk."