Cameroon's main parliament building in its capital Yaoundé was badly damaged by fire which ripped through four floors.
Firefighters managed to put out the blaze before it could reach the parliamentary chamber.
There is no indication of any casualties so far and the cause of the blaze was not immediately clear.
In this week's session, the national assembly had been discussing the budget.
Pictures and video posted on social media show the upper floors in flames, hours after it first took hold.