Two Libyan soldiers have been killed in Benghazi after a bomb was thrown at a checkpoint.<br /><br />It is the latest in a series of attacks against the security forces. <br /><br />The government is struggling to impose its authority over armed groups.<br /><br />And now they are helping to force elected officials from office.<br /><br />Al Jazeera's Ziena Khodr reports from Benghazi.