An Isis manufacturing facility that posed a “significant chemical [weapons] threat” has been destroyed in Iraq.

Footage of air strikes on Monday showed 12 aircraft from the US-led coalition bombarding a large industrial site in Mosul.

Huge explosions could be seen hitting multiple buildings and storage units, leaving them in flames with large plumes of smoke rising into the air.

The US Air Force released footage of air strikes on the Isis chemical weapons facility (US Air Forces)

Isis released a propaganda statement claiming American fighter jets had destroyed the “only pharmaceutical company in northern Mosul” but defence officials said jihadists had converted the factory to manufacture chemical weapons.

Lieutenant General Jeffrey Harrigian, from US Air Forces Central Command said the facility posed a “significant chemical threat to innocent Iraqis”.

“Intelligence had indicated that Daesh [Isis] converted a pharmaceutical plant complex into a chemical weapons productions capability,” he added, saying 50 individual targets were hit.

“This represents just another example of Daesh blatant disregard for international law and norms.

“The enemy is using innocent civilians as shields against our values and respect for human life.”

United Nations investigators have confirmed Isis’ use of mustard gas in both Syria and Iraq and the group has also been accused of using chlorine gas.

Both chemical weapons are toxic and can kill their victims, frequently causing breathing difficulties, blisters and internal injuries.

In pictures: Iraq battles to drive Isis out of Fallujah Show all 12 1 /12 In pictures: Iraq battles to drive Isis out of Fallujah In pictures: Iraq battles to drive Isis out of Fallujah Smoke rises after airstrikes by US-led coalition planes as Iraqi security forces advance against Islamic State extremists in Fallujah, June 15, 2016 AP In pictures: Iraq battles to drive Isis out of Fallujah Iraqi security forces advance during heavy fighting against Isis militants in Fallujah, Iraq, on 14 June AP In pictures: Iraq battles to drive Isis out of Fallujah Shia militia say that moving resources from Fallujah towards the area near Mosul was a 'betrayal' of the battle for the city GETTY In pictures: Iraq battles to drive Isis out of Fallujah Hospital sources said 18 bodies were recovered from the river over the weekend AP In pictures: Iraq battles to drive Isis out of Fallujah Up to 60,000 civilians were feared trapped in Fallujah at the start of the Iraqi operation AP In pictures: Iraq battles to drive Isis out of Fallujah Shia fighters hold an Isis flag in an operation east of Fallujah – the terror group has lost ground in both Syria and Iraq AFP/Getty In pictures: Iraq battles to drive Isis out of Fallujah Shia fighters hold their weapons as they gather near Falluja, Iraq, June 4, 2016. Reuters In pictures: Iraq battles to drive Isis out of Fallujah Pro-government forces bid to take back ground from Isis in Fallujah MOADH AL-DULAIMI/AFP/Getty Images In pictures: Iraq battles to drive Isis out of Fallujah Smoke billows on the horizon as Iraqi military forces prepare for an offensive to retake the city AP In pictures: Iraq battles to drive Isis out of Fallujah A member of the Iraqi security forces fires artillery during clashes with Isis militants near Fallujah, Iraq, 29 May, 2016 Reuters In pictures: Iraq battles to drive Isis out of Fallujah Iraqi government forces fire a rocket near al-Sejar village, north-east of Fallujah, on May 26, 2016, as they take part in a major assault to retake the city from the Islamic State group AFP/Getty In pictures: Iraq battles to drive Isis out of Fallujah Shia fighters and Iraqi security forces advance towards Fallujah Thaier Al-Sudani/Reuters

Speaking from the Al-Udeid Air Base in Qatar, Lt Gen Harrigian said the US Air Force would continue efforts to “dismantle Daesh” and accelerate ground operations to drive Isis out of Mosul and Raqqa.

“We will continue to shape the battle space, going after their revenue streams, killing their leaders and creating organisational dysfunction,” he added.

“We will seek to use the weight of air power to remove Daesh’s legitimacy, shatter their vision and enable taking back the territory and resources they have stolen.”

Mosul is Isis’ de-facto capital in Iraq and its only city stronghold remaining in the country after militants were driven out of Fallujah and Tikrit.

The Iraqi security forces, supported by Shia militias and the international coalition, have been advancing on the city for months in preparation for an all-out assault.

Air strikes have recently targeted Isis bomb-making facilities and oil tankers in preparation for the operation, which the UN has warned could trigger a “massive” humanitarian crisis.

British air strikes have recently been focused on the town of Qayyarah – 40 miles from Mosul – which was re-taken by Iraqi forces last month after two years under Isis control.