Libya’s capital has been rocked by heavy fighting between the two main armed groups linked to the Tripoli-based government, forcing a halt to flights from the city’s only civilian airport.The fighting between the 444 Brigade and the Al-Radaa Force, or Special Deterrence Force, erupted on Monday night and carried over into Tuesday, an interior ministry official said.”Clashes affected several areas of Tripoli’s eastern suburbs, in Ain Zara south of Tripoli, pitting the forces of 444 Brigade against those of Al-Radaa”, the official told AFP on condition of anonymity.There were no immediate reports of any casualties from the fighting which was still underway on Tuesday morning, and which the official said had forced “the closure of roads around Mitiga airport”.Images shared on social media late Monday showed armoured vehicles and armed pickups in the east and south of Tripoli after the arrest of 444 Brigade commander Mahmud Hamza at Mitiga airport, in an area under Al-Radaa’s control.”Tensions arose” soon after it was announced “the Al-Radaa Force had arrested the head of the 444 Brigade, without explaining whether this was on judicial orders or for other reasons”, the official said.Plumes of smoke were seen in Tripoli and gunfire was heard in the densely populated suburb of Ain Zara before it spread to areas near the airport and Tripoli University, which announced the suspension of classes.Air traffic was stopped at Mitiga airport and flights were diverted to Misrata, about 180 kilometres (110 miles) to the east, and aircraft that had been parked on the tarmac were moved away.Libya has been plagued by divisions fuelled by the proliferation of armed groups with shifting allegiances since the 2011 overthrow of dictator Moamer Kadhafi in a NATO-backed uprising.The 444 Brigade is affiliated with Libya’s defence ministry and is reputed to be the North African country’s most disciplined.It controls the southern suburbs of Tripoli as well as the cities of Tarhuna and Bani Walid, securing roads linking the capital to the south of the country.The Al-Radaa Force, commanded by Abdel Rauf Karah, is a powerful ultra-conservative militia that acts as Tripoli’s police force, arresting both suspected jihadists and common criminals.It positions itself as independent of the interior and defence ministries, and it controls central and eastern Tripoli and Mitiga air base, the civilian airport and a prison.