As the secretary exits the building, the protesters set fire to his office furniture.
Radio reports said several hundred protesters had set tires on fire and blocked streets.
At points, protesters set fires and turned over dumpsters.
The protesters set fire to a company bus and a police van, witnesses said.
Six months ago in Nice, protesters set a bank on fire and smashed windows of a dozen stores.
The protesters set the Parliament and president's offices on fire, images of which were broadcast around the world.
It followed a day of violence during which protesters set fire to a bank, killing three employees.
The protesters forced their way into the Government compound, and then set fire to several rooms and 10 vehicles, the agency said.
On Monday protesters set fire to the party headquarters building.
The protesters set fire to two cars and burnt down the headquarters of the traffic police.