Residents in northeastern Tehran awoke to a loud bang this morning, after Israeli jets struck a key target in Iran's nuclear programme.

A fire could be seen raging at the heavily sanctioned Imam Hossein University, where nuclear scientists work on producing weapons of mass destruction, under the close administration of the Islamic Revolutionary Guard Corps, according to experts at the Gulf International Forum.

The facility has been pointed to as a key centre for Iran's development and production of biological and nuclear weapons by alarmed governments.

Imam Hossein University was designated as centre for weapons of mass destruction manufacturing by the US Treasury in 2012 for “providing, or attempting to provide technological, and or other support for and services in support of the IRGC.”

The IRGC is an armed faction within Iran that functions outside of the military and directs much of the country's missile programme, with the stated aim of protecting the 1978 revolution.

This elite internal faction's control of Imam Hossein University makes it the only part of the Iranian nuclear programme that is out of the hands of the government and civil agencies.

This has led to accusations that the IRGC militants are 'secretly' the ones running the country's supposedly civilian nuclear development programme.

In a revealing interview with Iranian state media in 2017, IRGC Brigadier General Hamid Abazari said that the university had been sending fighters and "teachers" to foreign wars in order to harden them for modern combat.

The regime hardliner admitted: “We dispatched a number of commanders and teachers of Imam Hossein University to the resistance front to become familiar with proxy battlefields.

"Some of them were deployed to this mission once and others on several occasions. And this has had a great impact on the quality of their work and training,”

Images of smoke billowing from the university, which also contains an IRGC officer college, come as Israel's war with Iran enters its sixth day as tensions show no sign of relenting, with US President Trump considering getting involved in the conflict and demanding Iran's “unconditional surrender.”

The US has also shut its Jerusalem embassy until Friday amid the ever-heightening tensions and American military build-up in the region with the redeployment of the USS Nimitz strike group to the region, alongside sightings of additional air power moving to the Middle East.