Gunmen surrounded Libya’s foreign ministry on Sunday to push demands that officials who had worked for deposed dictator Muammar Gaddafi’s regime be banned from senior positions in the new administration.

At least 20 pick-up trucks loaded with anti-aircraft guns blocked the roads while men armed with AK-47 and sniper rifles directed the traffic away from the building, witnesses said.

Tension between the government and armed militias have been rising in recent weeks since a campaign was launched to dislodge the groups from their strongholds in the capital.