Militiamen besieged the headquarters of Libya’s Justice Ministry in Tripoli on 30 April demanding the government pass a law banning Gaddafi-era officials from working in official posts.

Armed men arrived in trucks mounted with anti-aircraft guns, blockading the ministry building in the Falah district of Tripoli, the local English language Libya Herald reports. They had previously attacked the Finance Ministry building.

The militiamen are demanding the government pass a controversial “political isolation law”, which would ban thousands of officials from office. Libya’s transitional parliament, the General National Congress (GNC), is due to debate the law on 5 May.

More peaceful protests over the law have also been seen outside the GNC building, where parliament had been suspended.

However, the siege of the ministry is part of a worrying trend. On 19 April, a report by Washington-based think-tank, the Atlantic Council highlighted the shortcomings of the current government in controlling the country effectively.

Towns liberated in the 2011 war were encouraged to set up their own military councils to oversee the increasing number of armed groups across Libya. The units’ loyalties are tied to specific communities, rather than the central government, which has been unable to bring them together.

“As long as quasi-independent militias play the role of army and police, the country will continue to face a series of grave security issues,” says the report.