An armed group reportedly stormed the building, which is in the centre of the city, and witnesses say they heard blasts and gunfire.

According to a security official at the site, at least two staff members and two gunmen were killed, and the NOC chairman was evacuated.

The attack comes as day after UNSMIL hosted a meeting in the western Libyan town of Zawiya, attended by the Libyan Government of National Accord, military and security chiefs, and armed groups present in around Tripoli.

That meeting ended with a commitment from those present to uphold a ceasefire agreed on 4 September, and develop a plan for withdrawing armed groups away from areas which include sovereign institutions and critical infrastructure, across the capital.

In a statement, UNSMIL described the assault on NOC – Libya’s primary source of national wealth – as “a blow against Libyans everywhere”, called on the country’s citizens to end conflicts and, in partnership with the international community, “eradicate the scourge of terrorism across the country.”

The Mission expressed its deepest condolences to the families of the victims and wished a speedy recovery to the injured.